* generic/tclEncoding.c (EscapeFromUtfProc):

	Clear the TCL_ENCODING_END flag when end
	bytes are written. This fix keep this method
	from writing escape bytes for an encoding
	like iso2022-jp multiple times when the
	escape byte overlap with the end of the
	IO buffer.
	* tests/io.test: Add test for escape
	byte overlap issue.

3 files changed, 87 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index b7496e6..ba6b105 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2006-12-26  Mo DeJong  <mdejong@users.sourceforge.net>
+
+	* generic/tclEncoding.c (EscapeFromUtfProc):
+	Clear the TCL_ENCODING_END flag when end
+	bytes are written. This fix keep this method
+	from writing escape bytes for an encoding
+	like iso2022-jp multiple times when the
+	escape byte overlap with the end of the
+	IO buffer.
+	* tests/io.test: Add test for escape
+	byte overlap issue.
+
 2006-12-19  Donal K. Fellows  <donal.k.fellows@man.ac.uk>
 
 	* unix/tclUnixThrd.c (Tcl_GetAllocMutex, TclpNewAllocMutex): Add
diff --git a/generic/tclEncoding.c b/generic/tclEncoding.c
index 69c7f28..11c838a 100644
--- a/generic/tclEncoding.c
+++ b/generic/tclEncoding.c
@@ -8,7 +8,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclEncoding.c,v 1.51 2006/11/13 08:23:07 das Exp $
+ * RCS: @(#) $Id: tclEncoding.c,v 1.52 2006/12/27 01:25:35 mdejong Exp $
  */
 
 #include "tclInt.h"
@@ -2981,7 +2981,7 @@ EscapeFromUtfProc(
 
     if (flags & TCL_ENCODING_START) {
 	state = 0;
-	if (dst + dataPtr->initLen > dstEnd) {
+	if ((dst + dataPtr->initLen) > dstEnd) {
 	    *srcReadPtr = 0;
 	    *dstWrotePtr = 0;
 	    return TCL_CONVERT_NOSPACE;
@@ -3089,7 +3089,17 @@ EscapeFromUtfProc(
 
     if ((result == TCL_OK) && (flags & TCL_ENCODING_END)) {
 	unsigned int len = dataPtr->subTables[0].sequenceLen;
-	if (dst + dataPtr->finalLen + (state?len:0) > dstEnd) {
+	/*
+	 * Certain encodings like iso2022-jp need to write
+	 * an escape sequence after all characters have
+	 * been converted. This logic checks that enough
+	 * room is available in the buffer for the escape bytes.
+	 * The TCL_ENCODING_END flag is cleared after a final
+	 * escape sequence has been added to the buffer so
+	 * that another call to this method does not attempt
+	 * to append escape bytes a second time.
+	 */
+	if ((dst + dataPtr->finalLen + (state?len:0)) > dstEnd) {
 	    result = TCL_CONVERT_NOSPACE;
 	} else {
 	    if (state) {
@@ -3100,6 +3110,7 @@ EscapeFromUtfProc(
 	    memcpy((VOID *) dst, (VOID *) dataPtr->final,
 		    (size_t) dataPtr->finalLen);
 	    dst += dataPtr->finalLen;
+	    state &= ~TCL_ENCODING_END;
 	}
     }
 
diff --git a/tests/io.test b/tests/io.test
index 7d1933e..2ba2183 100644
--- a/tests/io.test
+++ b/tests/io.test
@@ -13,7 +13,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: io.test,v 1.74 2006/11/03 11:45:34 dkf Exp $
+# RCS: @(#) $Id: io.test,v 1.75 2006/12/27 01:25:35 mdejong Exp $
 
 if {[catch {package require tcltest 2}]} {
     puts stderr "Skipping tests in [info script].  tcltest 2 required."
@@ -117,6 +117,66 @@ test io-1.8 {Tcl_WriteChars: WriteChars} {
     contents $path(test2)
 } "    \x1b\$B\$O\x1b(B"
 
+test io-1.9 {Tcl_WriteChars: WriteChars} {
+    # When closing a channel with an encoding that appends
+    # escape bytes, check for the case where the escape
+    # bytes overflow the current IO buffer. The bytes
+    # should be moved into a new buffer.
+
+    set data "1234567890 [format %c 12399]"
+
+    set sizes [list]
+
+    # With default buffer size
+    set f [open $path(test2) w]
+    fconfigure      $f -encoding iso2022-jp
+    puts -nonewline $f $data
+    close           $f
+    lappend sizes [file size $path(test2)]
+
+    # With buffer size equal to the length
+    # of the data, the escape bytes would
+    # go into the next buffer.
+
+    set f [open $path(test2) w]
+    fconfigure      $f -encoding iso2022-jp -buffersize 16
+    puts -nonewline $f $data
+    close           $f
+    lappend sizes [file size $path(test2)]
+
+    # With buffer size that is large enough
+    # to hold 1 byte of escaped data, but
+    # not all 3. This should not write
+    # the escape bytes to the first buffer
+    # and then again to the second buffer.
+
+    set f [open $path(test2) w]
+    fconfigure      $f -encoding iso2022-jp -buffersize 17
+    puts -nonewline $f $data
+    close           $f
+    lappend sizes [file size $path(test2)]
+
+    # With buffer size that can hold 2 out of
+    # 3 bytes of escaped data.
+
+    set f [open $path(test2) w]
+    fconfigure      $f -encoding iso2022-jp -buffersize 18
+    puts -nonewline $f $data
+    close           $f
+    lappend sizes [file size $path(test2)]
+
+    # With buffer size that can hold all the
+    # data and escape bytes.
+
+    set f [open $path(test2) w]
+    fconfigure      $f -encoding iso2022-jp -buffersize 19
+    puts -nonewline $f $data
+    close           $f
+    lappend sizes [file size $path(test2)]
+
+    set sizes
+} {19 19 19 19 19}
+
 test io-2.1 {WriteBytes} {
     # loop until all bytes are written