[TIP 412] msgcat dynamic locale change and package private locale (msgcat 1.6.0)

9 files changed, 1421 insertions, 187 deletions

diff --git a/ChangeLog b/ChangeLog
index bb441a5..e2881a0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -913,6 +913,14 @@ a better first place to look now.
 	* win/nmakehlp.c: Let "nmakehlp -V" start searching digits after the
 	found match (suggested by Harald Oehlmann).
 
+2012-09-19  Harald Oehlmann  <oehhar@users.sf.net>
+
+	IMPLEMENTATION OF TIP#412.
+
+	* library/msgcat/msgcat.tcl:	dynamic locale change with mc file
+	* library/clock.tcl:            load on locale change.
+	clock uses new msgcat features.
+
 2012-09-07  Harald Oehlmann  <oehhar@users.sf.net>
 
 	*** 8.6b3 TAGGED FOR RELEASE ***
diff --git a/changes b/changes
index 57f8f52..2084f80 100644
--- a/changes
+++ b/changes
@@ -8528,3 +8528,7 @@ include ::oo::class (fellows)
         *** POTENTIAL INCOMPATIBILITY ***
 
 --- Released 8.6.4, March 12, 2015 --- http://core.tcl.tk/tcl/ for details
+
+2015-06-25 (TIP 412) msgcat dynamic locale change and package private locale (oehlmann)
+=> msgcat 1.6.0
+
diff --git a/doc/msgcat.n b/doc/msgcat.n
index bae6dbe..7e46528 100644
--- a/doc/msgcat.n
+++ b/doc/msgcat.n
@@ -13,29 +13,43 @@ msgcat \- Tcl message catalog
 .SH SYNOPSIS
 \fBpackage require Tcl 8.5\fR
 .sp
-\fBpackage require msgcat 1.5\fR
+\fBpackage require msgcat 1.6\fR
 .sp
 \fB::msgcat::mc \fIsrc-string\fR ?\fIarg arg ...\fR?
 .sp
 \fB::msgcat::mcmax ?\fIsrc-string src-string ...\fR?
 .sp
+.VS "TIP 412"
+\fB::msgcat::mcexists\fR ?\fB-exactnamespace\fR? ?\fB-exactlocale\fR? \fIsrc-string\fR
+.VE "TIP 412"
+.sp
 \fB::msgcat::mclocale \fR?\fInewLocale\fR?
 .sp
 \fB::msgcat::mcpreferences\fR
 .sp
+.VS "TIP 412"
+\fB::msgcat::mcloadedlocales subcommand\fR ?\fIlocale\fR?
+.VE "TIP 412"
+.sp
 \fB::msgcat::mcload \fIdirname\fR
 .sp
 \fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR?
 .sp
 \fB::msgcat::mcmset \fIlocale src-trans-list\fR
 .sp
-.VS "TIP 404"
 \fB::msgcat::mcflset \fIsrc-string \fR?\fItranslate-string\fR?
 .sp
 \fB::msgcat::mcflmset \fIsrc-trans-list\fR
-.VE "TIP 404"
 .sp
 \fB::msgcat::mcunknown \fIlocale src-string\fR ?\fIarg arg ...\fR?
+.sp
+.VS "TIP 412"
+\fB::msgcat::mcpackagelocale subcommand\fR ?\fIlocale\fR?
+.sp
+\fB::msgcat::mcpackageconfig subcommand\fR \fIoption\fR ?\fIvalue\fR?
+.sp
+\fB::msgcat::mcforgetpackage\fR
+.VE "TIP 412"
 .BE
 .SH DESCRIPTION
 .PP
@@ -46,18 +60,23 @@ Text strings are defined in a
 which is independent from the application, and
 which can be edited or localized without modifying
 the application source code.  New languages
-or locales are provided by adding a new file to
+or locales may be provided by adding a new file to
 the message catalog.
 .PP
-Use of the message catalog is optional by any application
-or package, but is encouraged if the application or package
-wishes to be enabled for multi-lingual applications.
+\fBmsgcat\fR distinguises packages by its namespace.
+Each package has its own message catalog and configuration settings in \fBmsgcat\fR.
+.PP
+A \fIlocale\fR is a specification string describing a user language like \fBde_ch\fR for Swiss German.
+In \fBmsgcat\fR, there is a global locale initialized by the system locale of the current system.
+Each package may decide to use the global locale or to use a package specific locale.
+.PP
+The global locale may be changed on demand, for example by a user initiated language change or within a multi user application like a web server.
 .SH COMMANDS
 .TP
 \fB::msgcat::mc \fIsrc-string\fR ?\fIarg arg ...\fR?
 .
 Returns a translation of \fIsrc-string\fR according to the
-user's current locale.  If additional arguments past \fIsrc-string\fR
+current locale.  If additional arguments past \fIsrc-string\fR
 are given, the \fBformat\fR command is used to substitute the
 additional arguments in the translation of \fIsrc-string\fR.
 .RS
@@ -84,6 +103,18 @@ of the longest translated string.  This is useful when designing
 localized GUIs, which may require that all buttons, for example, be a
 fixed width (which will be the width of the widest button).
 .TP
+\fB::msgcat::mcexists\fR ?\fB-exactnamespace\fR? ?\fB-exactlocale\fR? \fIsrc-string\fR
+.
+.VS "TIP 412"
+Return true, if there is a translation for the given \fIsrc-string\fR.
+.PP
+.RS
+The search may be limited by the option \fB\-exactnamespace\fR to only check the current namespace and not any parent namespaces.
+.PP
+It may also be limited by the option \fB\-exactlocale\fR to only check the first prefered locale (e.g. first element returned by \fB::msgcat::mcpreferences\fR if global locale is used).
+.RE
+.VE "TIP 412"
+.TP
 \fB::msgcat::mclocale \fR?\fInewLocale\fR?
 .
 This function sets the locale to \fInewLocale\fR.  If \fInewLocale\fR
@@ -93,6 +124,13 @@ case-insensitive manner, and returns locales in lowercase.
 The initial locale is determined by the locale specified in
 the user's environment.  See \fBLOCALE SPECIFICATION\fR
 below for a description of the locale string format.
+.RS
+.PP
+.VS "TIP 412"
+If the locale is set, the preference list of locales is evaluated.
+Locales in this list are loaded now, if not jet loaded.
+.VE "TIP 412"
+.RE
 .TP
 \fB::msgcat::mcpreferences\fR
 .
@@ -103,13 +141,26 @@ preference.  The list is derived from the current
 locale set in msgcat by \fB::msgcat::mclocale\fR, and
 cannot be set independently.  For example, if the
 current locale is en_US_funky, then \fB::msgcat::mcpreferences\fR
-returns \fB{en_US_funky en_US en {}}\fR.
+returns \fB{en_us_funky en_us en {}}\fR.
+.TP
+\fB::msgcat:mcloadedlocales subcommand\fR ?\fIlocale\fR?
+.
+This group of commands manage the list of loaded locales for packages not setting a package locale.
+.PP
+.RS
+The subcommand \fBget\fR returns the list of currently loaded locales.
+.PP
+The subcommand \fBpresent\fR requires the argument \fIlocale\fR and returns true, if this locale is loaded.
+.PP
+The subcommand \fBclear\fR removes all locales and their data, which are not in the current preference list.
+.RE
 .TP
 \fB::msgcat::mcload \fIdirname\fR
 .
+.VS "TIP 412"
 Searches the specified directory for files that match
-the language specifications returned by \fB::msgcat::mcpreferences\fR
-(note that these are all lowercase), extended by the file extension
+the language specifications returned by \fB::msgcat::mcloadedlocales get\fR
+(or \fBmsgcat::mcpackagelocale preferences\fR if a package locale is set) (note that these are all lowercase), extended by the file extension
 .QW .msg .
 Each matching file is
 read in order, assuming a UTF-8 encoding.  The file contents are
@@ -118,6 +169,11 @@ may be present in the message file either directly in their UTF-8
 encoded form, or by use of the backslash-u quoting recognized by Tcl
 evaluation.  The number of message files which matched the specification
 and were loaded is returned.
+.RS
+.PP
+In addition, the given folder is stored in the \fBmsgcat\fR package configuration option \fImcfolder\fR to eventually load message catalog files required by a locale change.
+.VE "TIP 412"
+.RE
 .TP
 \fB::msgcat::mcset \fIlocale src-string \fR?\fItranslate-string\fR?
 .
@@ -138,16 +194,13 @@ faster than multiple invocations of \fB::msgcat::mcset\fR. The function
 returns the number of translations set.
 .TP
 \fB::msgcat::mcflset \fIsrc-string \fR?\fItranslate-string\fR?
-.VS "TIP 404"
 Sets the translation for \fIsrc-string\fR to \fItranslate-string\fR in the
 current namespace for the locale implied by the name of the message catalog
 being loaded via \fB::msgcat::mcload\fR.  If \fItranslate-string\fR is not
 specified, \fIsrc-string\fR is used for both.  The function returns
 \fItranslate-string\fR.
-.VE "TIP 404"
 .TP
 \fB::msgcat::mcflmset \fIsrc-trans-list\fR
-.VS "TIP 404"
 Sets the translation for multiple source strings in \fIsrc-trans-list\fR in
 the current namespace for the locale implied by the name of the message
 catalog being loaded via \fB::msgcat::mcload\fR. \fIsrc-trans-list\fR must
@@ -155,7 +208,6 @@ have an even number of elements and is in the form {\fIsrc-string
 translate-string\fR ?\fIsrc-string translate-string ...\fR?}
 \fB::msgcat::mcflmset\fR can be significantly faster than multiple invocations
 of \fB::msgcat::mcflset\fR. The function returns the number of translations set.
-.VE "TIP 404"
 .TP
 \fB::msgcat::mcunknown \fIlocale src-string\fR ?\fIarg arg ...\fR?
 .
@@ -168,7 +220,18 @@ application, for example to log error messages for each unknown
 string.  The \fB::msgcat::mcunknown\fR procedure is invoked at the
 same stack context as the call to \fB::msgcat::mc\fR.  The return value
 of \fB::msgcat::mcunknown\fR is used as the return value for the call
-to \fB::msgcat::mc\fR.  
+to \fB::msgcat::mc\fR.
+.VS "TIP 412"
+.RS
+.PP
+Note that this routine is only called if the concerned package did not set a package locale unknown command name.
+.RE
+.TP
+\fB::msgcat::mcforgetpackage\fR
+.
+The calling package clears all its state within the \fBmsgcat\fR package including all settings and translations.
+.VE "TIP 412"
+.PP
 .SH "LOCALE SPECIFICATION"
 .PP
 The locale is specified to \fBmsgcat\fR by a locale string
@@ -217,15 +280,15 @@ When a locale is specified by the user, a
 search is performed during string translation.  For example, if a user
 specifies
 en_GB_Funky, the locales
-.QW en_GB_Funky ,
-.QW en_GB ,
+.QW en_gb_funky ,
+.QW en_gb ,
 .QW en
 and
 .MT
 (the empty string)
 are searched in order until a matching translation
 string is found.  If no translation string is available, then
-\fB::msgcat::mcunknown\fR is called.
+the unknown handler is called.
 .SH "NAMESPACES AND MESSAGE CATALOGS"
 .PP
 Strings stored in the message catalog are stored relative
@@ -373,6 +436,209 @@ formatting substitution is done directly.
 # ... where that key is mapped to one of the
 # human-oriented versions by \fBmsgcat::mcset\fR
 .CE
+.VS "TIP 412"
+.SH Package private locale
+.PP
+A package using \fBmsgcat\fR may choose to use its own package private
+locale and its own set of loaded locales, independent to the global
+locale set by \fB::msgcat::mclocale\fR.
+.PP
+This allows a package to change its locale without causing any locales load or removal in other packages and not to invoke the global locale change callback (see below).
+.PP
+This action is controled by the following ensemble:
+.TP
+\fB::msgcat::mcpackagelocale set\fR ?\fIlocale\fR?
+.
+Set or change a package private locale.
+The package private locale is set to the given \fIlocale\fR if the \fIlocale\fR is given.
+If the option \fIlocale\fR is not given, the package is set to package private locale mode, but no locale is changed (e.g. if the global locale was valid for the package before, it is copied to the package private locale).
+.PP
+.RS
+This command may cause the load of locales.
+.RE
+.TP
+\fB::msgcat::mcpackagelocale get\fR
+.
+Return the package private locale or the global locale, if no package private locale is set.
+.TP
+\fB::msgcat::mcpackagelocale preferences\fR
+.
+Return the package private preferences or the global preferences,
+if no package private locale is set.
+.TP
+\fB::msgcat::mcpackagelocale loaded\fR
+.
+Return the list of locales loaded for this package.
+.TP
+\fB::msgcat::mcpackagelocale isset\fR
+.
+Returns true, if a package private locale is set.
+.TP
+\fB::msgcat::mcpackagelocale unset\fR
+.
+Unset the package private locale and use the globale locale.
+Load and remove locales to adjust the list of loaded locales for the
+package to the global loaded locales list.
+.TP
+\fB::msgcat::mcpackagelocale present\fR \fIlocale\fR
+.
+Returns true, if the given locale is loaded for the package.
+.TP
+\fB::msgcat::mcpackagelocale clear\fR
+.
+Clear any loaded locales of the package not present in the package preferences.
+.PP
+.SH Changing package options
+.PP
+Each package using msgcat has a set of options within \fBmsgcat\fR.
+The package options are described in the next sectionPackage options.
+Each package option may be set or unset individually using the following ensemble:
+.TP
+\fB::msgcat::mcpackageconfig get\fR \fIoption\fR
+.
+Return the current value of the given \fIoption\fR.
+This call returns an error if the option is not set for the package.
+.TP
+\fB::msgcat::mcpackageconfig isset\fR \fIoption\fR
+.
+Returns 1, if the given \fIoption\fR is set for the package, 0 otherwise.
+.TP
+\fB::msgcat::mcpackageconfig set\fR \fIoption\fR \fIvalue\fR
+.
+Set the given \fIoption\fR to the given \fIvalue\fR.
+This may invoke additional actions in dependency of the \fIoption\fR.
+The return value is 0 or the number of loaded packages for the option \fBmcfolder\fR.
+.TP
+\fB::msgcat::mcpackageconfig unset\fR \fIoption\fR
+.
+Unsets the given \fIoption\fR for the package.
+No action is taken if the \fIoption\fR is not set for the package.
+The empty string is returned.
+.SS Package options
+.PP
+The following package options are available for each package:
+.TP
+\fBmcfolder\fR
+.
+This is the message folder of the package. This option is set by mcload and by the subcommand set. Both are identical and both return the number of loaded message catalog files.
+.RS
+.PP
+Setting or changing this value will load all locales contained in the preferences valid for the package. This implies also to invoke any set loadcmd (see below).
+.PP
+Unsetting this value will disable message file load for the package.
+.RE
+.TP
+\fBloadcmd\fR
+.
+This callback is invoked before a set of message catalog files are loaded for the package which has this property set.
+.PP
+.RS
+This callback may be used to do any preparation work for message file load or to get the message data from another source like a data base. In this case, no message files are used (mcfolder is unset).
+.PP
+See section \fBcallback invocation\fR below.
+The parameter list appended to this callback is the list of locales to load.
+.PP
+If this callback is changed, it is called with the preferences valid for the package.
+.RE
+.TP
+\fBchangecmd\fR
+.
+This callback is invoked when a default local change was performed. Its purpose is to allow a package to update any dependency on the default locale like showing the GUI in another language.
+.PP
+.RS
+See the callback invocation section below.
+The parameter list appended to this callback is \fBmcpreferences\fR.
+The registered callbacks are invoked in no particular order.
+.RE
+.TP
+\fBunknowncmd\fR
+.
+Use a package locale mcunknown procedure instead of the standard version supplied by the msgcat package (msgcat::mcunknown).
+.PP
+.RS
+The called procedure must return the formatted message which will finally be returned by msgcat::mc.
+.PP
+A generic unknown handler is used if set to the empty string. This consists in returning the key if no arguments are given. With given arguments, format is used to process the arguments.
+.PP
+See section \fBcallback invocation\fR below.
+The appended arguments are identical to \fB::msgcat::mcunknown\fR.
+.RE
+.SS Callback invocation
+A package may decide to register one or multiple callbacks, as described above.
+.PP
+Callbacks are invoked, if:
+.PP
+1. the callback command is set,
+.PP
+2. the command is not the empty string,
+.PP
+3. the registering namespace exists.
+.PP
+If a called routine fails with an error, the \fBbgerror\fR routine for the interpreter is invoked after command completion.
+Only exception is the callback \fBunknowncmd\fR, where an error causes the invoking \fBmc\fR-command to fail with that error.
+.PP
+.SS Examples
+Packages which display a GUI may update their widgets when the global locale changes.
+To register to a callback, use:
+.CS
+namespace eval gui {
+    msgcat::mcpackageconfig changecmd updateGUI
+
+    proc updateGui args {
+        puts "New locale is '[lindex $args 0]'."
+    }
+}
+% msgcat::mclocale fr
+fr
+% New locale is 'fr'.
+.CE
+.PP
+If locales (or additional locales) are contained in another source like a data base, a package may use the load callback and not mcload:
+.CS
+namespace eval db {
+    msgcat::mcpackageconfig loadcmd loadMessages
+
+    proc loadMessages args {
+        foreach locale $args {
+            if {[LocaleInDB $locale]} {
+                msgcat::mcmset $locale [GetLocaleList $locale]
+            }
+        }
+    }
+}
+.CE
+.PP
+The \fBclock\fR command implementation uses \fBmsgcat\fR with a package locale to implement the command line parameter \fB-locale\fR.
+Here are some sketches of the implementation:
+.PP
+First, a package locale is initialized and the generic unknown function is desactivated:
+.CS
+msgcat::mcpackagelocale set
+msgcat::mcpackageconfig unknowncmd ""
+.CE
+As an example, the user requires the week day in a certain locale as follows:
+.CS
+clock format clock seconds -format %A -locale fr
+.CE
+\fBclock\fR sets the package locale to \fBfr\fR and looks for the day name as follows:
+.CS
+msgcat::mcpackagelocale set $locale
+return [lindex [msgcat::mc DAYS_OF_WEEK_FULL] $day]
+### Returns "mercredi"
+.CE
+Within \fBclock\fR, some message-catalog items are heavy in computation and thus are dynamically cached using:
+.CS
+proc ::tcl::clock::LocalizeFormat { locale format } {
+    set key FORMAT_$format
+    if { [::msgcat::mcexists -exactlocale -exactnamespace $key] } {
+        return [mc $key]
+    }
+    #...expensive computation of format clipped...
+    mcset $locale $key $format
+    return $format
+}
+.CE
+.VE "TIP 412"
 .SH CREDITS
 .PP
 The message catalog code was developed by Mark Harrison.
diff --git a/library/clock.tcl b/library/clock.tcl
index 67d15b1..e995bd1 100644
--- a/library/clock.tcl
+++ b/library/clock.tcl
@@ -19,7 +19,7 @@
 # access to the Registry on Windows systems.
 
 uplevel \#0 {
-    package require msgcat 1.4
+    package require msgcat 1.6
     if { $::tcl_platform(platform) eq {windows} } {
 	if { [catch { package require registry 1.1 }] } {
 	    namespace eval ::tcl::clock [list variable NoRegistry {}]
@@ -60,6 +60,8 @@ namespace eval ::tcl::clock {
 
     namespace import ::msgcat::mcload
     namespace import ::msgcat::mclocale
+    namespace import ::msgcat::mc
+    namespace import ::msgcat::mcpackagelocale
 
 }
 
@@ -106,6 +108,10 @@ proc ::tcl::clock::Initialize {} {
     }
     InitTZData
 
+    mcpackagelocale set {}
+    ::msgcat::mcpackageconfig set mcfolder [file join $LibDir msgs]
+    ::msgcat::mcpackageconfig set unknowncmd ""
+
     # Define the message catalog for the root locale.
 
     ::msgcat::mcmset {} {
@@ -249,7 +255,6 @@ proc ::tcl::clock::Initialize {} {
     # Define the directories for time zone data and message catalogs.
 
     variable DataDir [file join $LibDir tzdata]
-    variable MsgDir [file join $LibDir msgs]
 
     # Number of days in the months, in common years and leap years.
 
@@ -623,11 +628,6 @@ proc ::tcl::clock::Initialize {} {
 					# in the given locales and dictionaries
 					# mapping the numerals to their numeric
 					# values.
-    variable McLoaded {};		# Dictionary whose keys are locales
-					# in which [mcload] has been executed
-					# and whose values are second-level
-    					# dictionaries indexed by message
-    					# name and giving message text.
     # variable CachedSystemTimeZone;    # If 'CachedSystemTimeZone' exists,
 					# it contains the value of the
 					# system time zone, as determined from
@@ -659,6 +659,7 @@ proc ::tcl::clock::Initialize {} {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::format { args } {
+
     variable FormatProc
     variable TZData
 
@@ -692,6 +693,7 @@ proc ::tcl::clock::format { args } {
     }
 
     return [$procName $clockval $timezone]
+
 }
 
 #----------------------------------------------------------------------
@@ -710,13 +712,14 @@ proc ::tcl::clock::format { args } {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::ParseClockFormatFormat {procName format locale} {
+
     if {[namespace which $procName] ne {}} {
 	return $procName
     }
 
     # Map away the locale-dependent composite format groups
 
-    EnterLocale $locale oldLocale
+    EnterLocale $locale
 
     # Change locale if a fresh locale has been given on the command line.
 
@@ -725,12 +728,6 @@ proc ::tcl::clock::ParseClockFormatFormat {procName format locale} {
     } trap CLOCK {result opts} {
 	dict unset opts -errorinfo
 	return -options $opts $result
-    } finally {
-	# Restore the locale
-
-	if { [info exists oldLocale] } {
-	    mclocale $oldLocale
-	}
     }
 }
 
@@ -1181,6 +1178,7 @@ proc ::tcl::clock::ParseClockFormatFormat2 {format locale procName} {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::scan { args } {
+
     set format {}
 
     # Check the count of args
@@ -1264,7 +1262,7 @@ proc ::tcl::clock::scan { args } {
 
     # Change locale if a fresh locale has been given on the command line.
 
-    EnterLocale $locale oldLocale
+    EnterLocale $locale
 
     try {
 	# Map away the locale-dependent composite format groups
@@ -1273,15 +1271,8 @@ proc ::tcl::clock::scan { args } {
 	return [$scanner $string $base $timezone]
     } trap CLOCK {result opts} {
 	# Conceal location of generation of expected errors
-
 	dict unset opts -errorinfo
 	return -options $opts $result
-    } finally {
-	# Restore the locale
-
-	if { [info exists oldLocale] } {
-	    mclocale $oldLocale
-	}
     }
 }
 
@@ -1304,6 +1295,7 @@ proc ::tcl::clock::scan { args } {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::FreeScan { string base timezone locale } {
+
     variable TZData
 
     # Get the data for time changes in the given zone
@@ -1431,6 +1423,7 @@ proc ::tcl::clock::FreeScan { string base timezone locale } {
 	set date2 [ConvertLocalToUTC $date2[set date2 {}] $TZData($timezone) \
 		       2361222]
 	set seconds [dict get $date2 seconds]
+
     }
 
     # Do relative month
@@ -2155,6 +2148,7 @@ proc ::tcl::clock::UniquePrefixRegexp { data } {
 proc ::tcl::clock::MakeUniquePrefixRegexp { successors
 					  uniquePrefixMapping
 					  prefixString } {
+
     # Get the characters that may follow the current prefix string
 
     set schars [lsort -ascii [dict keys [dict get $successors $prefixString]]]
@@ -2224,6 +2218,7 @@ proc ::tcl::clock::MakeUniquePrefixRegexp { successors
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::MakeParseCodeFromFields { dateFields parseActions } {
+
     set currPrio 999
     set currFieldPos [list]
     set currCodeBurst {
@@ -2297,26 +2292,16 @@ proc ::tcl::clock::MakeParseCodeFromFields { dateFields parseActions } {
 #
 # Parameters:
 #	locale -- Desired locale
-#	oldLocaleVar -- Name of a variable in caller's scope that
-#		        tracks the previous locale name.
 #
 # Results:
 #	Returns the locale that was previously current.
 #
 # Side effects:
-#	Does [mclocale].  If necessary, uses [mcload] to load the designated
-#	locale's files, and tracks that it has done so in the 'McLoaded'
-#	variable.
+#	Does [mclocale].  If necessary, loades the designated locale's files.
 #
 #----------------------------------------------------------------------
 
-proc ::tcl::clock::EnterLocale { locale oldLocaleVar } {
-    upvar 1 $oldLocaleVar oldLocale
-
-    variable MsgDir
-    variable McLoaded
-
-    set oldLocale [mclocale]
+proc ::tcl::clock::EnterLocale { locale } {
     if { $locale eq {system} } {
 	if { $::tcl_platform(platform) ne {windows} } {
 	    # On a non-windows platform, the 'system' locale is the same as
@@ -2329,33 +2314,22 @@ proc ::tcl::clock::EnterLocale { locale oldLocaleVar } {
 	    # Control Panel.  First, load the 'current' locale if it's not yet
 	    # loaded
 
-	    if {![dict exists $McLoaded $oldLocale] } {
-		mcload $MsgDir
-		dict set McLoaded $oldLocale {}
-	    }
+	    mcpackagelocale set [mclocale]
 
 	    # Make a new locale string for the system locale, and get the
 	    # Control Panel information
 
-	    set locale ${oldLocale}_windows
-	    if { ![dict exists $McLoaded $locale] } {
+	    set locale [mclocale]_windows
+	    if { $locale ni [::msgcat::mcpackagelocale loaded] } {
 		LoadWindowsDateTimeFormats $locale
-		dict set McLoaded $locale {}
 	    }
 	}
     }
     if { $locale eq {current}} {
-	set locale $oldLocale
-	unset oldLocale
-    } elseif { $locale eq $oldLocale } {
-	unset oldLocale
-    } else {
-	mclocale $locale
-    }
-    if { ![dict exists $McLoaded $locale] } {
-	mcload $MsgDir
-	dict set McLoaded $locale {}
+	set locale [mclocale]
     }
+    # Eventually load the locale
+    mcpackagelocale set $locale
 }
 
 #----------------------------------------------------------------------
@@ -2482,6 +2456,7 @@ proc ::tcl::clock::LoadWindowsDateTimeFormats { locale } {
     }
 
     return
+
 }
 
 #----------------------------------------------------------------------
@@ -2505,13 +2480,13 @@ proc ::tcl::clock::LoadWindowsDateTimeFormats { locale } {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::LocalizeFormat { locale format } {
-    variable McLoaded
 
-    if { [dict exists $McLoaded $locale FORMAT $format] } {
-	return [dict get $McLoaded $locale FORMAT $format]
-    }
-    set inFormat $format
+    # message catalog key to cache this format
+    set key FORMAT_$format
 
+    if { [::msgcat::mcexists -exactlocale -exactnamespace $key] } {
+	return [mc $key]
+    }
     # Handle locale-dependent format groups by mapping them out of the format
     # string.  Note that the order of the [string map] operations is
     # significant because later formats can refer to later ones; for example
@@ -2534,7 +2509,7 @@ proc ::tcl::clock::LocalizeFormat { locale format } {
     lappend list %Ec [string map $list [mc LOCALE_DATE_TIME_FORMAT]]
     set format [string map $list $format]
 
-    dict set McLoaded $locale FORMAT $inFormat $format
+    ::msgcat::mcset $locale $key $format
     return $format
 }
 
@@ -3133,7 +3108,6 @@ proc ::tcl::clock::SetupTimeZone { timezone } {
 		    -errorcode [list CLOCK badTimeZone $timezone] \
 		    "time zone \"$timezone\" not found"
 	    }
-
 	} elseif { ![catch {ParsePosixTimeZone $timezone} tzfields] } {
 	    # This looks like a POSIX time zone - try to process it
 
@@ -3901,6 +3875,7 @@ proc ::tcl::clock::ProcessPosixTimeZone { z } {
 #----------------------------------------------------------------------
 
 proc ::tcl::clock::DeterminePosixDSTTime { z bound y } {
+
     variable FEB_28
 
     # Determine the start or end day of DST
@@ -3908,6 +3883,7 @@ proc ::tcl::clock::DeterminePosixDSTTime { z bound y } {
     set date [dict create era CE year $y]
     set doy [dict get $z ${bound}DayOfYear]
     if { $doy ne {} } {
+
 	# Time was specified as a day of the year
 
 	if { [dict get $z ${bound}J] ne {}
@@ -4319,7 +4295,7 @@ proc ::tcl::clock::add { clockval args } {
 	set timezone :GMT
     }
 
-    EnterLocale $locale oldLocale
+    EnterLocale $locale
 
     set changeover [mc GREGORIAN_CHANGE_DATE]
 
@@ -4371,12 +4347,6 @@ proc ::tcl::clock::add { clockval args } {
 	# Conceal the innards of [clock] when it's an expected error
 	dict unset opts -errorinfo
 	return -options $opts $result
-    } finally {
-	# Restore the locale
-
-	if { [info exists oldLocale] } {
-	    mclocale $oldLocale
-	}
     }
 }
 
@@ -4449,6 +4419,7 @@ proc ::tcl::clock::AddMonths { months clockval timezone changeover } {
 		 $changeover]
 
     return [dict get $date seconds]
+
 }
 
 #----------------------------------------------------------------------
@@ -4499,38 +4470,7 @@ proc ::tcl::clock::AddDays { days clockval timezone changeover } {
 		  $changeover]
 
     return [dict get $date seconds]
-}
-
-#----------------------------------------------------------------------
-#
-# mc --
-#
-#	Wrapper around ::msgcat::mc that caches the result according to the
-#	locale.
-#
-# Parameters:
-#	Accepts the name of the message to retrieve.
-#
-# Results:
-#	Returns the message text.
-#
-# Side effects:
-#	Caches the message text.
-#
-# Notes:
-#	Only the single-argument version of [mc] is supported.
-#
-#----------------------------------------------------------------------
 
-proc ::tcl::clock::mc { name } {
-    variable McLoaded
-    set Locale [mclocale]
-    if { [dict exists $McLoaded $Locale $name] } {
-	return [dict get $McLoaded $Locale $name]
-    }
-    set val [::msgcat::mc $name]
-    dict set McLoaded $Locale $name $val
-    return $val
 }
 
 #----------------------------------------------------------------------
@@ -4553,7 +4493,6 @@ proc ::tcl::clock::mc { name } {
 proc ::tcl::clock::ClearCaches {} {
     variable FormatProc
     variable LocaleNumeralCache
-    variable McLoaded
     variable CachedSystemTimeZone
     variable TimeZoneBad
 
@@ -4566,7 +4505,6 @@ proc ::tcl::clock::ClearCaches {} {
 
     catch {unset FormatProc}
     set LocaleNumeralCache {}
-    set McLoaded {}
     catch {unset CachedSystemTimeZone}
     set TimeZoneBad {}
     InitTZData
diff --git a/library/msgcat/msgcat.tcl b/library/msgcat/msgcat.tcl
index cf3b9d7..5ed9f3a 100644
--- a/library/msgcat/msgcat.tcl
+++ b/library/msgcat/msgcat.tcl
@@ -4,6 +4,7 @@
 #	message catalog facility for Tcl programs.  It should be
 #	loaded with the command "package require msgcat".
 #
+# Copyright (c) 2010-2015 by Harald Oehlmann.
 # Copyright (c) 1998-2000 by Ajuba Solutions.
 # Copyright (c) 1998 by Mark Harrison.
 #
@@ -13,23 +14,30 @@
 package require Tcl 8.5
 # When the version number changes, be sure to update the pkgIndex.tcl file,
 # and the installation directory in the Makefiles.
-package provide msgcat 1.5.2
+package provide msgcat 1.6.0
 
 namespace eval msgcat {
-    namespace export mc mcload mclocale mcmax mcmset mcpreferences mcset \
-	    mcunknown mcflset mcflmset
-
-    # Records the current locale as passed to mclocale
-    variable Locale ""
+    namespace export mc mcexists mcload mclocale mcmax mcmset mcpreferences mcset\
+            mcunknown mcflset mcflmset mcloadedlocales mcforgetpackage\
+	    mcpackageconfig mcpackagelocale
 
     # Records the list of locales to search
     variable Loclist {}
 
+    # List of currently loaded locales
+    variable LoadedLocales {}
+
     # Records the locale of the currently sourced message catalogue file
     variable FileLocale
 
+    # Configuration values per Package (e.g. client namespace).
+    # The dict key is of the form "<option> <namespace>" and the value is the
+    # configuration option. A nonexisting key is an unset option.
+    variable PackageConfig [dict create mcfolder {} loadcmd {} changecmd {}\
+	    unknowncmd {} loadedlocales {} loclist {}]
+
     # Records the mapping between source strings and translated strings.  The
-    # dict key is of the form "<locale> <namespace> <src>", where locale and
+    # dict key is of the form "<namespace> <locale> <src>", where locale and
     # namespace should be themselves dict values and the value is
     # the translated string.
     variable Msgs [dict create]
@@ -173,6 +181,8 @@ namespace eval msgcat {
 #	parent namespace until the source is found.  If additional args are
 #	specified, use the format command to work them into the traslated
 #	string.
+#	If no catalog item is found, mcunknown is called in the caller frame
+#	and its result is returned.
 #
 # Arguments:
 #	src	The string to translate.
@@ -183,30 +193,86 @@ namespace eval msgcat {
 #	format command.
 
 proc msgcat::mc {src args} {
+    # this may be replaced by:
+    # return [mcget -namespace [uplevel 1 [list ::namespace current]] --\
+    #	    $src {*}$args]
+
     # Check for the src in each namespace starting from the local and
     # ending in the global.
 
     variable Msgs
     variable Loclist
-    variable Locale
 
     set ns [uplevel 1 [list ::namespace current]]
+    set loclist [PackagePreferences $ns]
 
-    while {$ns != ""} {
-	foreach loc $Loclist {
-	    if {[dict exists $Msgs $loc $ns $src]} {
-		if {[llength $args] == 0} {
-		    return [dict get $Msgs $loc $ns $src]
-		} else {
-		    return [format [dict get $Msgs $loc $ns $src] {*}$args]
-		}
+    set nscur $ns
+    while {$nscur != ""} {
+	foreach loc $loclist {
+	    if {[dict exists $Msgs $nscur $loc $src]} {
+		return [DefaultUnknown "" [dict get $Msgs $nscur $loc $src]\
+			{*}$args]
 	    }
 	}
+	set nscur [namespace parent $nscur]
+    }
+    # call package local or default unknown command
+    set args [linsert $args 0 [lindex $loclist 0] $src]
+    switch -exact -- [Invoke unknowncmd $args $ns result 1] {
+	0 { return [uplevel 1 [linsert $args 0 [namespace origin mcunknown]]] }
+	1 { return [DefaultUnknown {*}$args] }
+	default { return $result }
+    }
+}
+
+# msgcat::mcexists --
+#
+#	Check if a catalog item is set or if mc would invoke mcunknown.
+#
+# Arguments:
+#	-exactnamespace		Only check the exact namespace and no
+#				parent namespaces
+#	-exactlocale		Only check the exact locale and not all members
+#				of the preferences list
+#	src			Message catalog key
+#
+# Results:
+#	true if an adequate catalog key was found
+
+proc msgcat::mcexists {args} {
+
+    variable Msgs
+    variable Loclist
+    variable PackageConfig
+
+    set ns [uplevel 1 [list ::namespace current]]
+    set loclist [PackagePreferences $ns]
+
+    while {[llength $args] != 1} {
+	set args [lassign $args option]
+	switch -glob -- $option {
+	    -exactnamespace { set exactnamespace 1 }
+	    -exactlocale { set loclist [lrange $loclist 0 0] }
+	    -* { return -code error "unknown option \"$option\"" }
+	    default {
+		return -code error "wrong # args: should be\
+			\"[lindex [info level 0] 0] ?-exactnamespace?\
+			?-exactlocale? src\""
+	    }
+	}
+    }
+    set src [lindex $args 0]
+    
+    while {$ns ne ""} {
+	foreach loc $loclist {
+	    if {[dict exists $Msgs $ns $loc $src]} {
+		return 1
+	    }
+	}
+	if {[info exists exactnamespace]} {return 0}
 	set ns [namespace parent $ns]
     }
-    # we have not found the translation
-    return [uplevel 1 [list [namespace origin mcunknown] \
-	    $Locale $src {*}$args]]
+    return 0
 }
 
 # msgcat::mclocale --
@@ -219,11 +285,11 @@ proc msgcat::mc {src args} {
 #			separated by underscores (e.g. en_US).
 #
 # Results:
-#	Returns the current locale.
+#	Returns the normalized set locale.
 
 proc msgcat::mclocale {args} {
     variable Loclist
-    variable Locale
+    variable LoadedLocales
     set len [llength $args]
 
     if {$len > 1} {
@@ -232,24 +298,49 @@ proc msgcat::mclocale {args} {
     }
 
     if {$len == 1} {
-	set newLocale [lindex $args 0]
+	set newLocale [string tolower [lindex $args 0]]
 	if {$newLocale ne [file tail $newLocale]} {
 	    return -code error "invalid newLocale value \"$newLocale\":\
 		    could be path to unsafe code."
 	}
-	set Locale [string tolower $newLocale]
-	set Loclist {}
-	set word ""
-	foreach part [split $Locale _] {
-	    set word [string trim "${word}_${part}" _]
-	    if {$word ne [lindex $Loclist 0]} {
-		set Loclist [linsert $Loclist 0 $word]
-	    }
+	if {[lindex $Loclist 0] ne $newLocale} {
+	    set Loclist [GetPreferences $newLocale]
+	    
+	    # locale not loaded jet
+	    LoadAll $Loclist
+	    # Invoke callback
+	    Invoke changecmd $Loclist
+	}
+    }
+    return [lindex $Loclist 0]
+}
+
+# msgcat::GetPreferences --
+#
+#	Get list of locales from a locale.
+#	The first element is always the lowercase locale.
+#	Other elements have one component separated by "_" less.
+#	Multiple "_" are seen as one separator: de__ch_spec de__ch de {}
+#
+# Arguments:
+#	Locale.
+#
+# Results:
+#	Locale list
+
+proc msgcat::GetPreferences {locale} {
+    set locale [string tolower $locale]
+    set loclist [list $locale]
+    while {-1 !=[set pos [string last "_" $locale]]} {
+	set locale [string range $locale 0 $pos-1]
+	if { "_" ne [string index $locale end] } {
+	    lappend loclist $locale
 	}
-	lappend Loclist {}
-	set Locale [lindex $Loclist 0]
     }
-    return $Locale
+    if {"" ne [lindex $loclist end]} {
+	lappend loclist {}
+    }
+    return $loclist
 }
 
 # msgcat::mcpreferences --
@@ -268,6 +359,391 @@ proc msgcat::mcpreferences {} {
     return $Loclist
 }
 
+# msgcat::mcloadedlocales --
+#
+#	Get or change the list of currently loaded default locales
+#
+#	The following subcommands are available:
+#	loaded
+#	    Get the current list of loaded locales
+#	clear
+#	    Remove all loaded locales not present in mcpreferences.
+#
+# Arguments:
+#	subcommand		One of loaded or clear
+#
+# Results:
+#	Empty string, if not stated differently for the subcommand
+
+proc msgcat::mcloadedlocales {subcommand} {
+    variable Loclist
+    variable LoadedLocales
+    variable Msgs
+    variable PackageConfig
+    switch -exact -- $subcommand {
+	clear {
+	    # Remove all locales not contained in Loclist
+	    # skip any packages with package locale
+	    set LoadedLocales $Loclist
+	    foreach ns [dict keys $Msgs] {
+		if {![dict exists $PackageConfig loclist $ns]} {
+		    foreach locale [dict keys [dict get $Msgs $ns]] {
+			if {$locale ni $Loclist} {
+			    dict unset Msgs $ns $locale
+			}
+		    }
+		}
+	    }
+	}
+	loaded { return $LoadedLocales }
+	default {
+	    return -code error "unknown subcommand \"$subcommand\": must be\
+		    clear, or loaded"
+	}
+    }
+    return
+}
+
+# msgcat::mcpackagelocale --
+#
+#	Get or change the package locale of the calling package.
+#
+#	The following subcommands are available:
+#	set
+#	    Set a package locale.
+#	    This may load message catalog files and may clear message catalog
+#	    items, if the former locale was the default locale.
+#	    Returns the normalized set locale.
+#	    The default locale is taken, if locale is not given.
+#	get
+#	    Get the locale valid for this package.
+#	isset
+#	    Returns true, if a package locale is set
+#	unset
+#	    Unset the package locale and activate the default locale.
+#	    This loads message catalog file which where missing in the package
+#	    locale.
+#	preferences
+#	    Return locale preference list valid for the package.
+#	loaded
+#	    Return loaded locale list valid for the current package.
+#	clear
+#	    If the current package has a package locale, remove all package
+#	    locales not containes in package mcpreferences.
+#	    It is an error to call this without a package locale set.
+#
+#	The subcommands get, preferences and loaded return the corresponding
+#	default data, if no package locale is set.
+#
+# Arguments:
+#	subcommand		see list above
+#	locale			package locale (only set subcommand)
+#
+# Results:
+#	Empty string, if not stated differently for the subcommand
+
+proc msgcat::mcpackagelocale {subcommand {locale ""}} {
+    # todo: implement using an ensemble
+    variable Loclist
+    variable LoadedLocales
+    variable Msgs
+    variable PackageConfig
+    # Check option
+    # check if required item is exactly provided
+    if {[llength [info level 0]] == 2} {
+	# locale not given
+	unset locale
+    } else {
+	# locale given
+	if {$subcommand in
+		{"get" "isset" "unset" "preferences" "loaded" "clear"} } {
+	    return -code error "wrong # args: should be\
+		    \"[lrange [info level 0] 0 1]\""
+	}
+        set locale [string tolower $locale]
+    }
+    set ns [uplevel 1 {::namespace current}]
+    
+    switch -exact -- $subcommand {
+	get { return [lindex [PackagePreferences $ns] 0] }
+	preferences { return [PackagePreferences $ns] }
+	loaded { return [PackageLocales $ns] }
+	present { return [expr {$locale in [PackageLocales $ns]} ]}
+	isset { return [dict exists $PackageConfig loclist $ns] }
+	set { # set a package locale or add a package locale
+
+	    # Copy the default locale if no package locale set so far
+	    if {![dict exists $PackageConfig loclist $ns]} {
+		dict set PackageConfig loclist $ns $Loclist
+		dict set PackageConfig loadedlocales $ns $LoadedLocales
+	    }
+
+	    # Check if changed
+	    set loclist [dict get $PackageConfig loclist $ns]
+	    if {! [info exists locale] || $locale eq [lindex $loclist 0] } {
+		return [lindex $loclist 0]
+	    }
+
+	    # Change loclist
+	    set loclist [GetPreferences $locale]
+	    set locale [lindex $loclist 0]
+	    dict set PackageConfig loclist $ns $loclist
+
+	    # load eventual missing locales
+	    set loadedLocales [dict get $PackageConfig loadedlocales $ns]
+	    if {$locale in $loadedLocales} { return $locale }
+	    set loadLocales [ListComplement $loadedLocales $loclist]
+	    dict set PackageConfig loadedlocales $ns\
+		    [concat $loadedLocales $loadLocales]
+	    Load $ns $loadLocales
+	    return $locale
+	}
+	clear { # Remove all locales not contained in Loclist
+	    if {![dict exists $PackageConfig loclist $ns]} {
+		return -code error "clear only when package locale set"
+	    }
+	    set loclist [dict get $PackageConfig loclist $ns]
+	    dict set PackageConfig loadedlocales $ns $loclist
+	    if {[dict exists $Msgs $ns]} {
+		foreach locale [dict keys [dict get $Msgs $ns]] {
+		    if {$locale ni $loclist} {
+			dict unset Msgs $ns $locale
+		    }
+		}
+	    }
+	}
+	unset {	# unset package locale and restore default locales
+
+	    if { ![dict exists $PackageConfig loclist $ns] } { return }
+
+	    # unset package locale
+	    set loadLocales [ListComplement\
+		    [dict get $PackageConfig loadedlocales $ns] $LoadedLocales]
+	    dict unset PackageConfig loadedlocales $ns
+	    dict unset PackageConfig loclist $ns
+
+	    # unset keys not in global loaded locales
+	    if {[dict exists $Msgs $ns]} {
+		foreach locale [dict keys [dict get $Msgs $ns]] {
+		    if {$locale ni $LoadedLocales} {
+			dict unset Msgs $ns $locale
+		    }
+		}
+	    }
+
+	    # Add missing locales
+	    Load $ns $loadLocales
+	}
+	default {
+	    return -code error "unknown subcommand \"$subcommand\": must be\
+		    clear, get, isset, loaded, present, set, or unset"
+	}
+    }
+    return
+}
+
+# msgcat::mcforgetpackage --
+#
+#	Remove any data of the calling package from msgcat
+#
+
+proc msgcat::mcforgetpackage {} {
+    # todo: this may be implemented using an ensemble
+    variable PackageConfig
+    variable Msgs
+    set ns [uplevel 1 {::namespace current}]
+    # Remove MC items
+    dict unset Msgs $ns
+    # Remove config items
+    foreach key [dict keys $PackageConfig] {
+	dict unset PackageConfig $key $ns
+    }
+    return
+}
+
+# msgcat::mcpackageconfig --
+#
+#	Get or modify the per caller namespace (e.g. packages) config options.
+#
+#	Available subcommands are:
+#
+#	    get		get the current value or an error if not set.
+#	    isset	return true, if the option is set
+#	    set		set the value (see also distinct option).
+#			Returns the number of loaded message files.
+#	    unset	Clear option. return "".
+#
+#	Available options are:
+#
+#	mcfolder
+#	    The message catalog folder of the package.
+#	    This is automatically set by mcload.
+#	    If the value is changed using the set subcommand, an evntual
+#	    loadcmd is invoked and all message files of the package locale are
+#	    loaded.
+#
+#	loadcmd
+#	    The command gets executed before a message file would be
+#	    sourced for this module.
+#	    The command is invoked with the expanded locale list to load.
+#	    The command is not invoked if the registering package namespace
+#	    is not present.
+#	    This callback might also be used as an alternative to message
+#	    files.
+#	    If the value is changed using the set subcommand, the callback is
+#	    directly invoked with the current file locale list. No file load is
+#	    executed.
+#
+#	changecmd
+#	    The command is invoked, after an executed locale change.
+#	    Appended argument is expanded mcpreferences.
+#
+#	unknowncmd
+#	    Use a package locale mcunknown procedure instead the global one.
+#	    The appended arguments are identical to mcunknown.
+#	    A default unknown handler is used if set to the empty string.
+#	    This consists in returning the key if no arguments are given.
+#	    With given arguments, format is used to process the arguments.
+#
+# Arguments:
+#	subcommand		Operation on the package
+#	option			The package option to get or set.
+#	?value?			Eventual value for the subcommand
+#
+# Results:
+#	Depends on the subcommand and option and is described there
+
+proc msgcat::mcpackageconfig {subcommand option {value ""}} {
+    variable PackageConfig
+    # get namespace
+    set ns [uplevel 1 {::namespace current}]
+
+    if {$option ni {"mcfolder" "loadcmd" "changecmd" "unknowncmd"}} {
+	return -code error "bad option \"$option\": must be mcfolder, loadcmd,\
+		changecmd, or unknowncmd"
+    }
+
+    # check if value argument is exactly provided
+    if {[llength [info level 0]] == 4 } {
+	# value provided
+	if {$subcommand in {"get" "isset" "unset"}} {
+	    return -code error "wrong # args: should be\
+		    \"[lrange [info level 0] 0 2] value\""
+	}
+    } elseif {$subcommand eq "set"} {
+        return -code error\
+		"wrong # args: should be \"[lrange [info level 0] 0 2]\""
+    }
+
+    # Execute subcommands
+    switch -exact -- $subcommand {
+	get {	# Operation get return current value
+	    if {![dict exists $PackageConfig $option $ns]} {
+		return -code error "package option \"$option\" not set"
+	    }
+	    return [dict get $PackageConfig $option $ns]
+	}
+	isset {	return [dict exists $PackageConfig $option $ns] }
+	unset {	dict unset PackageConfig $option $ns }
+	set {	# Set option
+	
+	    if {$option eq "mcfolder"} {
+		set value [file normalize $value]
+	    }
+	    # Check if changed
+	    if { [dict exists $PackageConfig $option $ns]
+		    && $value eq [dict get $PackageConfig $option $ns] } {
+		return 0
+	    }
+
+	    # set new value
+	    dict set PackageConfig $option $ns $value
+
+	    # Reload pending message catalogs
+	    switch -exact -- $option {
+		mcfolder { return [Load $ns [PackageLocales $ns]] }
+		loadcmd { return [Load $ns [PackageLocales $ns] 1] }
+	    }
+	    return 0
+	}
+	default {
+	    return -code error "unknown subcommand \"$subcommand\":\
+		    must be get, isset, set, or unset"
+	}
+    }
+    return
+}
+
+# msgcat::PackagePreferences --
+#
+#	Return eventual present package preferences or the default list if not
+#	present.
+#
+# Arguments:
+#	ns		Package namespace
+#
+# Results:
+#	locale list
+
+proc msgcat::PackagePreferences {ns} {
+    variable PackageConfig
+    if {[dict exists $PackageConfig loclist $ns]} {
+	return [dict get $PackageConfig loclist $ns]
+    }
+    variable Loclist
+    return $Loclist
+}
+
+# msgcat::PackageLocales --
+#
+#	Return eventual present package locales or the default list if not
+#	present.
+#
+# Arguments:
+#	ns		Package namespace
+#
+# Results:
+#	locale list
+
+proc msgcat::PackageLocales {ns} {
+    variable PackageConfig
+    if {[dict exists $PackageConfig loadedlocales $ns]} {
+	return [dict get $PackageConfig loadedlocales $ns]
+    }
+    variable LoadedLocales
+    return $LoadedLocales
+}
+
+# msgcat::ListComplement --
+#
+#	Build the complement of two lists.
+#	Return a list with all elements in list2 but not in list1.
+#	Optionally return the intersection.
+#
+# Arguments:
+#	list1		excluded list
+#	list2		included list
+#	inlistname	If not "", write in this variable the intersection list
+#
+# Results:
+#	list with all elements in list2 but not in list1
+
+proc msgcat::ListComplement {list1 list2 {inlistname ""}} {
+    if {"" ne $inlistname} {
+	upvar 1 $inlistname inlist
+    }
+    set inlist {}
+    set outlist {}
+    foreach item $list2 {
+	if {$item in $list1} {
+	    lappend inlist $item
+	} else {
+	    lappend outlist $item
+	}
+    }
+    return $outlist
+}
+
 # msgcat::mcload --
 #
 #	Attempt to load message catalogs for each locale in the
@@ -280,24 +756,88 @@ proc msgcat::mcpreferences {} {
 #	Returns the number of message catalogs that were loaded.
 
 proc msgcat::mcload {langdir} {
+    return [uplevel 1 [list\
+	    [namespace origin mcpackageconfig] set mcfolder $langdir]]
+}
+
+# msgcat::LoadAll --
+#
+#	Load a list of locales for all packages not having a package locale
+#	list.
+#
+# Arguments:
+#	langdir		The directory to search.
+#
+# Results:
+#	Returns the number of message catalogs that were loaded.
+
+proc msgcat::LoadAll {locales} {
+    variable PackageConfig
+    variable LoadedLocales
+    if {0 == [llength $locales]} { return {} }
+    # filter jet unloaded locales
+    set locales [ListComplement $LoadedLocales $locales]
+    if {0 == [llength $locales]} { return {} }
+    lappend LoadedLocales {*}$locales
+    
+    set packages [lsort -unique [concat\
+	    [dict keys [dict get $PackageConfig loadcmd]]\
+	    [dict keys [dict get $PackageConfig mcfolder]]]]
+    foreach ns $packages {
+	if {! [dict exists $PackageConfig loclist $ns] } {
+	    Load $ns $locales
+	}
+    }
+    return $locales
+}
+
+# msgcat::Load --
+#
+#	Invoke message load callback and load message catalog files.
+#
+# Arguments:
+#	ns		Namespace (equal package) to load the message catalog.
+#	locales		List of locales to load.
+#	callbackonly	true if only callback should be invoked
+#
+# Results:
+#	Returns the number of message catalogs that were loaded.
+
+proc msgcat::Load {ns locales {callbackonly 0}} {
     variable FileLocale
+    variable PackageConfig
+    variable LoadedLocals
+
+    if {0 == [llength $locales]} { return 0 }
+
+    # Invoke callback
+    Invoke loadcmd $locales $ns
+    
+    if {$callbackonly || ![dict exists $PackageConfig mcfolder $ns]} {
+	return 0
+    }
+
+    # Invoke file load
+    set langdir [dict get $PackageConfig mcfolder $ns]
+    
     # Save the file locale if we are recursively called
     if {[info exists FileLocale]} {
 	set nestedFileLocale $FileLocale
     }
     set x 0
-    foreach p [mcpreferences] {
+    foreach p $locales {
 	if {$p eq {}} {
 	    set p ROOT
 	}
 	set langfile [file join $langdir $p.msg]
 	if {[file exists $langfile]} {
 	    incr x
-	    set FileLocale [string tolower [file tail [file rootname $langfile]]]
+	    set FileLocale [string tolower\
+		    [file tail [file rootname $langfile]]]
 	    if {"root" eq $FileLocale} {
 		set FileLocale ""
 	    }
-	    uplevel 1 [list ::source -encoding utf-8 $langfile]
+	    namespace inscope $ns [list ::source -encoding utf-8 $langfile]
 	    unset FileLocale
 	}
     }
@@ -307,6 +847,63 @@ proc msgcat::mcload {langdir} {
     return $x
 }
 
+# msgcat::Invoke --
+#
+#	Invoke a set of registered callbacks.
+#	The callback is only invoked, if its registered namespace exists.
+#
+# Arguments:
+#	index		Index into PackageConfig to get callback command
+#	arglist		parameters to the callback invocation
+#	ns		(Optional) package to call.
+#			If not given or empty, check all registered packages.
+#	resultname	Variable to save the callback result of the last called
+#			callback to. May be set to "" to discard the result.
+#	failerror (0)	Fail on error if true. Otherwise call bgerror.
+#
+# Results:
+#	Possible values:
+#	- 0: no valid command registered
+#	- 1: registered command was the empty string
+#	- 2: registered command called, resultname is set
+#	- 3: registered command failed
+#	If multiple commands are called, the maximum of all results is returned.
+
+proc msgcat::Invoke {index arglist {ns ""} {resultname ""} {failerror 0}} {
+    variable PackageConfig
+    variable Config
+    if {"" ne $resultname} {
+	upvar 1 $resultname result
+    }
+    if {"" eq $ns} {
+	set packageList [dict keys [dict get $PackageConfig $index]]
+    } else {
+	set packageList [list $ns]
+    }
+    set ret 0
+    foreach ns $packageList {
+	if {[dict exists $PackageConfig $index $ns] && [namespace exists $ns]} {
+	    set cmd [dict get $PackageConfig $index $ns]
+	    if {"" eq $cmd} {
+		if {$ret == 0} {set ret 1}
+	    } else {
+		if {$failerror} {
+		    set result [namespace inscope $ns $cmd {*}$arglist]
+		    set ret 2
+		} elseif {1 == [catch {
+		    set result [namespace inscope $ns $cmd {*}$arglist]
+		    if {$ret < 2} {set ret 2}
+		} err derr]} {
+		    after idle [concat [::interp bgerror ""]\
+			    [list $err $derr]]
+		    set ret 3
+		}
+	    }
+	}
+    }
+    return $ret
+}
+
 # msgcat::mcset --
 #
 #	Set the translation for a given string in a specified locale.
@@ -330,7 +927,7 @@ proc msgcat::mcset {locale src {dest ""}} {
 
     set locale [string tolower $locale]
 
-    dict set Msgs $locale $ns $src $dest
+    dict set Msgs $ns $locale $src $dest
     return $dest
 }
 
@@ -351,16 +948,10 @@ proc msgcat::mcflset {src {dest ""}} {
     variable Msgs
 
     if {![info exists FileLocale]} {
-	return -code error \
-	    "must only be used inside a message catalog loaded with ::msgcat::mcload"
-    }
-    if {[llength [info level 0]] == 2} { ;# dest not specified
-	set dest $src
+	return -code error "must only be used inside a message catalog loaded\
+		with ::msgcat::mcload"
     }
-
-    set ns [uplevel 1 [list ::namespace current]]
-    dict set Msgs $FileLocale $ns $src $dest
-    return $dest
+    return [uplevel 1 [list [namespace origin mcset] $FileLocale $src $dest]]
 }
 
 # msgcat::mcmset --
@@ -380,14 +971,14 @@ proc msgcat::mcmset {locale pairs} {
     set length [llength $pairs]
     if {$length % 2} {
 	return -code error "bad translation list:\
-		 should be \"[lindex [info level 0] 0] locale {src dest ...}\""
+		should be \"[lindex [info level 0] 0] locale {src dest ...}\""
     }
 
     set locale [string tolower $locale]
     set ns [uplevel 1 [list ::namespace current]]
 
     foreach {src dest} $pairs {
-	dict set Msgs $locale $ns $src $dest
+	dict set Msgs $ns $locale $src $dest
     }
 
     return [expr {$length / 2}]
@@ -408,26 +999,17 @@ proc msgcat::mcflmset {pairs} {
     variable Msgs
 
     if {![info exists FileLocale]} {
-	return -code error \
-	    "must only be used inside a message catalog loaded with ::msgcat::mcload"
-    }
-    set length [llength $pairs]
-    if {$length % 2} {
-	return -code error "bad translation list:\
-		should be \"[lindex [info level 0] 0] locale {src dest ...}\""
+	return -code error "must only be used inside a message catalog loaded\
+		with ::msgcat::mcload"
     }
-
-    set ns [uplevel 1 [list ::namespace current]]
-    foreach {src dest} $pairs {
-	dict set Msgs $FileLocale $ns $src $dest
-    }
-    return [expr {$length / 2}]
+    return [uplevel 1 [list [namespace origin mcmset] $FileLocale $pairs]]
 }
 
 # msgcat::mcunknown --
 #
 #	This routine is called by msgcat::mc if a translation cannot
-#	be found for a string.  This routine is intended to be replaced
+#	be found for a string and no unknowncmd is set for the current
+#	package. This routine is intended to be replaced
 #	by an application specific routine for error reporting
 #	purposes.  The default behavior is to return the source string.
 #	If additional args are specified, the format command will be used
@@ -441,7 +1023,30 @@ proc msgcat::mcflmset {pairs} {
 # Results:
 #	Returns the translated value.
 
-proc msgcat::mcunknown {locale src args} {
+proc msgcat::mcunknown {args} {
+    return [uplevel 1 [list [namespace origin DefaultUnknown] {*}$args]]
+}
+
+# msgcat::DefaultUnknown --
+#
+#	This routine is called by msgcat::mc if a translation cannot
+#	be found for a string in the following circumstances:
+#	- Default global handler, if mcunknown is not redefined.
+#	- Per package handler, if the package sets unknowncmd to the empty
+#	  string.
+#	It returna the source string if the argument list is empty.
+#	If additional args are specified, the format command will be used
+#	to work them into the traslated string.
+#
+# Arguments:
+#	locale		(unused) The current locale.
+#	src		The string to be translated.
+#	args		Args to pass to the format command
+#
+# Results:
+#	Returns the translated value.
+
+proc msgcat::DefaultUnknown {locale src args} {
     if {[llength $args]} {
 	return [format $src {*}$args]
     } else {
diff --git a/library/msgcat/pkgIndex.tcl b/library/msgcat/pkgIndex.tcl
index 5fabfe3..7399c92 100644
--- a/library/msgcat/pkgIndex.tcl
+++ b/library/msgcat/pkgIndex.tcl
@@ -1,2 +1,2 @@
 if {![package vsatisfies [package provide Tcl] 8.5]} {return}
-package ifneeded msgcat 1.5.2 [list source [file join $dir msgcat.tcl]]
+package ifneeded msgcat 1.6.0 [list source [file join $dir msgcat.tcl]]
diff --git a/tests/msgcat.test b/tests/msgcat.test
index 050b592..6b965d1 100644
--- a/tests/msgcat.test
+++ b/tests/msgcat.test
@@ -17,8 +17,8 @@ if {[catch {package require tcltest 2}]} {
     puts stderr "Skipping tests in [info script].  tcltest 2 required."
     return
 }
-if {[catch {package require msgcat 1.5}]} {
-    puts stderr "Skipping tests in [info script].  No msgcat 1.5 found to test."
+if {[catch {package require msgcat 1.6}]} {
+    puts stderr "Skipping tests in [info script].  No msgcat 1.6 found to test."
     return
 }
 
@@ -32,6 +32,8 @@ namespace eval ::msgcat::test {
 
     # Tests msgcat-0.*: locale initialization
 
+    # Calculate set of all permutations of a list
+    # PowerSet {1 2 3} -> {1 2 3} {2 3} {1 3} 3 {1 2} 2 1 {}
     proc PowerSet {l} {
 	if {[llength $l] == 0} {return [list [list]]}
 	set element [lindex $l 0]
@@ -412,9 +414,14 @@ namespace eval ::msgcat::test {
     foreach loc {foo foo_BAR foo_BAR_baz} {
 	test msgcat-5.$count {mcload} -setup {
 	    variable locale [mclocale]
+	    ::msgcat::mclocale ""
+	    ::msgcat::mcloadedlocales clear
+	    ::msgcat::mcpackageconfig unset mcfolder 
 	    mclocale $loc
 	} -cleanup {
 	    mclocale $locale
+	    ::msgcat::mcloadedlocales clear
+	    ::msgcat::mcpackageconfig unset mcfolder 
 	} -body {
 	    mcload $msgdir
 	} -result [expr { $count+1 }]
@@ -428,6 +435,8 @@ namespace eval ::msgcat::test {
 	    mclocale foo_BAR_notexist
 	} -cleanup {
 	    mclocale $locale
+	    mcloadedlocales clear
+	    mcpackageconfig unset mcfolder 
 	} -body {
 	    mcload $msgdir
 	} -result 3
@@ -437,6 +446,8 @@ namespace eval ::msgcat::test {
 	    mclocale no_FI_notexist
 	} -cleanup {
 	    mclocale $locale
+	    mcloadedlocales clear
+	    mcpackageconfig unset mcfolder 
 	} -body {
 	    mcload $msgdir
 	} -result 1
@@ -497,6 +508,20 @@ namespace eval ::msgcat::test {
 	    mc def
 	} -result unknown:no_fi_notexist:def
 
+	test msgcat-5.11 {mcpackageconfig mcfolder} -setup {
+	    variable locale [mclocale]
+	    mclocale ""
+	    mcloadedlocales clear
+	    mcpackageconfig unset mcfolder
+	} -cleanup {
+	    mclocale $locale
+	    mcloadedlocales clear
+	    mcpackageconfig unset mcfolder 
+	} -body {
+	    mclocale foo
+	    mcpackageconfig set mcfolder $msgdir
+	} -result 2
+
     foreach loc $locales {
 	if { $loc eq {} } {
 	    set msg ROOT
@@ -657,6 +682,394 @@ namespace eval ::msgcat::test {
     removeDirectory msgdir2
     removeDirectory msgdir3
 
+    # Tests msgcat-9.*: [mcexists]
+
+	test msgcat-9.1 {mcexists no parameter} -body {
+	    mcexists
+	} -returnCodes 1\
+	-result {wrong # args: should be "mcexists ?-exactnamespace? ?-exactlocale? src"}
+    
+	test msgcat-9.2 {mcexists unknown option} -body {
+	    mcexists -unknown src 
+	} -returnCodes 1\
+	-result {unknown option "-unknown"}
+    
+	test msgcat-9.3 {mcexists} -setup {
+	    mcforgetpackage
+	    variable locale [mclocale]
+	    mclocale foo
+	    mcset foo k1 v1
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    list [mcexists k1] [mcexists k2]
+	} -result {1 0}
+
+	test msgcat-9.4 {mcexists descendent preference} -setup {
+	    mcforgetpackage
+	    variable locale [mclocale]
+	    mclocale foo_bar
+	    mcset foo k1 v1
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    list [mcexists k1] [mcexists -exactlocale k1]
+	} -result {1 0}
+    
+	test msgcat-9.5 {mcexists parent namespace} -setup {
+	    mcforgetpackage
+	    variable locale [mclocale]
+	    mclocale foo_bar
+	    mcset foo k1 v1
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    namespace eval ::msgcat::test::sub {
+		list [::msgcat::mcexists k1]\
+			[::msgcat::mcexists -exactnamespace k1]
+	    }
+	} -result {1 0}
+    
+    # Tests msgcat-10.*: [mcloadedlocales]
+
+	test msgcat-10.1 {mcloadedlocales no arg} -body {
+	    mcloadedlocales
+	} -returnCodes 1\
+	-result {wrong # args: should be "mcloadedlocales subcommand"}
+    
+	test msgcat-10.2 {mcloadedlocales wrong subcommand} -body {
+	    mcloadedlocales junk
+	} -returnCodes 1\
+	-result {unknown subcommand "junk": must be clear, or loaded}
+    
+	test msgcat-10.3 {mcloadedlocales loaded} -setup {
+	    mcforgetpackage
+	    variable locale [mclocale]
+	    mclocale {}
+	    mcloadedlocales clear
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    mclocale foo_bar
+	    # The result is position independent so sort
+	    set resultlist [lsort [mcloadedlocales loaded]]
+	} -result {{} foo foo_bar}
+    
+	test msgcat-10.4 {mcloadedlocales clear} -setup {
+	    mcforgetpackage
+	    variable locale [mclocale]
+	    mclocale {}
+	    mcloadedlocales clear
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    mclocale foo
+	    mcset foo k1 v1
+	    set res [mcexists k1]
+	    mclocale ""
+	    mcloadedlocales clear
+	    mclocale foo
+	    lappend res [mcexists k1]
+	} -result {1 0}
+
+    # Tests msgcat-11.*: [mcforgetpackage]
+
+	test msgcat-11.1 {mcforgetpackage translation} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    mclocale foo
+	    mcset foo k1 v1
+	    set res [mcexists k1]
+	    mcforgetpackage
+	    lappend res [mcexists k1]
+	} -result {1 0}
+
+	test msgcat-11.2 {mcforgetpackage locale} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	} -body {
+	    mclocale foo
+	    mcpackagelocale set bar
+	    set res [mcpackagelocale get]
+	    mcforgetpackage
+	    lappend res [mcpackagelocale get]
+	} -result {bar foo}
+
+	test msgcat-11.3 {mcforgetpackage options} -body {
+	    mcpackageconfig set loadcmd ""
+	    set res [mcpackageconfig isset loadcmd]
+	    mcforgetpackage
+	    lappend res [mcpackageconfig isset loadcmd]
+	} -result {1 0}
+
+    # Tests msgcat-12.*: [mcpackagelocale]
+
+	test msgcat-12.1 {mcpackagelocale no subcommand} -body {
+	    mcpackagelocale
+	} -returnCodes 1\
+	-result {wrong # args: should be "mcpackagelocale subcommand ?locale?"}
+
+	test msgcat-12.2 {mclpackagelocale wrong subcommand} -body {
+	    mcpackagelocale junk
+	} -returnCodes 1\
+	-result {unknown subcommand "junk": must be clear, get, isset, loaded, present, set, or unset}
+
+	test msgcat-12.3 {mcpackagelocale set} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale foo
+	    mcpackagelocale set bar
+	    list [mcpackagelocale get] [mclocale]
+	} -result {bar foo}
+
+	test msgcat-12.4 {mcpackagelocale get} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale foo
+	    set res [mcpackagelocale get]
+	    mcpackagelocale set bar
+	    lappend res [mcpackagelocale get]
+	} -result {foo bar}
+
+	test msgcat-12.5 {mcpackagelocale preferences} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale foo
+	    set res [list [mcpackagelocale preferences]]
+	    mcpackagelocale set bar
+	    lappend res [mcpackagelocale preferences]
+	} -result {{foo {}} {bar {}}}
+
+	test msgcat-12.6 {mcpackagelocale loaded} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale ""
+	    mcloadedlocales clear
+	    mclocale foo
+	    # The result is position independent so sort
+	    set res [list [lsort [mcpackagelocale loaded]]]
+	    mcpackagelocale set bar
+	    lappend res [lsort [mcpackagelocale loaded]]
+	} -result {{{} foo} {{} bar foo}}
+
+	test msgcat-12.7 {mcpackagelocale isset} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale foo
+	    set res [mcpackagelocale isset]
+	    mcpackagelocale set bar
+	    lappend res [mcpackagelocale isset]
+	} -result {0 1}
+
+	test msgcat-12.8 {mcpackagelocale unset} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mcpackagelocale set bar
+	    set res [mcpackagelocale isset]
+	    mcpackagelocale unset
+	    lappend res [mcpackagelocale isset]
+	} -result {1 0}
+
+	test msgcat-12.9 {mcpackagelocale present} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale ""
+	    mcloadedlocales clear
+	    mclocale foo
+	    set res [mcpackagelocale present foo]
+	    lappend res [mcpackagelocale present bar]
+	    mcpackagelocale set bar
+	    lappend res [mcpackagelocale present foo]\
+		    [mcpackagelocale present bar]
+	} -result {1 0 1 1}
+
+	test msgcat-12.10 {mcpackagelocale clear} -setup {
+	    variable locale [mclocale]
+	} -cleanup {
+	    mclocale $locale
+	    mcforgetpackage
+	} -body {
+	    mclocale ""
+	    mcloadedlocales clear
+	    mclocale foo
+	    mcpackagelocale set bar
+	    mcpackagelocale clear
+	    list [mcpackagelocale present foo] [mcpackagelocale present bar]
+	} -result {0 1}
+
+    # Tests msgcat-13.*: [mcpackageconfig subcmds]
+
+	test msgcat-13.1 {mcpackageconfig no subcommand} -body {
+	    mcpackageconfig
+	} -returnCodes 1\
+	-result {wrong # args: should be "mcpackageconfig subcommand option ?value?"}
+
+	test msgcat-13.2 {mclpackageconfig wrong subcommand} -body {
+	    mcpackageconfig junk mcfolder
+	} -returnCodes 1\
+	-result {unknown subcommand "junk": must be get, isset, set, or unset}
+
+	test msgcat-13.3 {mclpackageconfig wrong option} -body {
+	    mcpackageconfig get junk
+	} -returnCodes 1\
+	-result {bad option "junk": must be mcfolder, loadcmd, changecmd, or unknowncmd}
+
+	test msgcat-13.4 {mcpackageconfig get} -setup {
+	    mcforgetpackage
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set loadcmd ""
+	    mcpackageconfig get loadcmd
+	} -result {}
+
+	test msgcat-13.5 {mcpackageconfig (is/un)set} -setup {
+	    mcforgetpackage
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    set res [mcpackageconfig isset loadcmd]
+	    lappend res [mcpackageconfig set loadcmd ""]
+	    lappend res [mcpackageconfig isset loadcmd]
+	    mcpackageconfig unset loadcmd
+	    lappend res [mcpackageconfig isset loadcmd]
+	} -result {0 0 1 0}
+
+    # option mcfolder is already tested with 5.11
+    
+    # Tests msgcat-14.*: callbacks: loadcmd, changecmd, unknowncmd
+    
+    # This routine is used as bgerror and by direct callback invocation
+    proc callbackproc args {
+	variable resultvariable
+	set resultvariable $args
+    }
+    proc callbackfailproc args {
+	return -code error fail
+    }
+    set bgerrorsaved [interp bgerror {}]
+    interp bgerror {} [namespace code callbackproc]
+    
+	test msgcat-14.1 {invokation loadcmd} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    mcloadedlocales clear
+	    set resultvariable ""
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set loadcmd [namespace code callbackproc]
+	    mclocale foo_bar
+	    lsort $resultvariable
+	} -result {foo foo_bar}
+
+	test msgcat-14.2 {invokation failed in loadcmd} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    mcloadedlocales clear
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set loadcmd [namespace code callbackfailproc]
+	    mclocale foo_bar
+	    # let the bgerror run
+	    after 100 set [namespace current]::resultvariable timeout
+	    vwait [namespace current]::resultvariable
+	    lassign $resultvariable err errdict
+	    list $err [dict get $errdict -code]
+	} -result {fail 1}
+
+	test msgcat-14.3 {invokation changecmd} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    set resultvariable ""
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set changecmd [namespace code callbackproc]
+	    mclocale foo_bar
+	    set resultvariable
+	} -result {foo_bar foo {}}
+
+	test msgcat-14.4 {invokation unknowncmd} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    mcloadedlocales clear
+	    set resultvariable ""
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set unknowncmd [namespace code callbackproc]
+	    mclocale foo_bar
+	    mc k1 p1
+	    set resultvariable
+	} -result {foo_bar k1 p1}
+
+	test msgcat-14.5 {disable global unknowncmd} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    mcloadedlocales clear
+	    set resultvariable ""
+	    rename ::msgcat::mcunknown SavedMcunknown
+	    proc ::msgcat::mcunknown {dom s} {
+		return unknown:$dom:$s
+	    }
+	} -cleanup {
+	    mcforgetpackage
+	    rename ::msgcat::mcunknown {}
+	    rename SavedMcunknown ::msgcat::mcunknown
+	} -body {
+	    mcpackageconfig set unknowncmd ""
+	    mclocale foo_bar
+	    mc k1%s p1
+	} -result {k1p1}
+
+	test msgcat-14.6 {unknowncmd failing} -setup {
+	    mcforgetpackage
+    	    mclocale $locale
+	    mclocale ""
+	    mcloadedlocales clear
+	    set resultvariable ""
+	} -cleanup {
+	    mcforgetpackage
+	} -body {
+	    mcpackageconfig set unknowncmd [namespace code callbackfailproc]
+	    mclocale foo_bar
+	    mc k1
+	} -returnCodes 1\
+	-result {fail}
+
+    interp bgerror {} $bgerrorsaved
+
     cleanupTests
 }
 namespace delete ::msgcat::test
diff --git a/unix/Makefile.in b/unix/Makefile.in
index e6908ec..cf28c6c 100644
--- a/unix/Makefile.in
+++ b/unix/Makefile.in
@@ -847,8 +847,8 @@ install-libraries: libraries
 	    do \
 	    $(INSTALL_DATA) $$i "$(SCRIPT_INSTALL_DIR)"/opt0.4; \
 	    done;
-	@echo "Installing package msgcat 1.5.2 as a Tcl Module";
-	@$(INSTALL_DATA) $(TOP_DIR)/library/msgcat/msgcat.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/msgcat-1.5.2.tm;
+	@echo "Installing package msgcat 1.6.0 as a Tcl Module";
+	@$(INSTALL_DATA) $(TOP_DIR)/library/msgcat/msgcat.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/msgcat-1.6.0.tm;
 	@echo "Installing package tcltest 2.3.8 as a Tcl Module";
 	@$(INSTALL_DATA) $(TOP_DIR)/library/tcltest/tcltest.tcl "$(SCRIPT_INSTALL_DIR)"/../tcl8/8.5/tcltest-2.3.8.tm;
 
diff --git a/win/Makefile.in b/win/Makefile.in
index 690d476..b92a062 100644
--- a/win/Makefile.in
+++ b/win/Makefile.in
@@ -650,8 +650,8 @@ install-libraries: libraries install-tzdata install-msgs
 	    do \
 	    $(COPY) "$$j" "$(SCRIPT_INSTALL_DIR)/opt0.4"; \
 	    done;
-	@echo "Installing package msgcat 1.5.2 as a Tcl Module";
-	@$(COPY) $(ROOT_DIR)/library/msgcat/msgcat.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/msgcat-1.5.2.tm;
+	@echo "Installing package msgcat 1.6.0 as a Tcl Module";
+	@$(COPY) $(ROOT_DIR)/library/msgcat/msgcat.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/msgcat-1.6.0.tm;
 	@echo "Installing package tcltest 2.3.8 as a Tcl Module";
 	@$(COPY) $(ROOT_DIR)/library/tcltest/tcltest.tcl $(SCRIPT_INSTALL_DIR)/../tcl8/8.5/tcltest-2.3.8.tm;
 	@echo "Installing package platform 1.0.13 as a Tcl Module";