* generic/tclIO.c (CopyData): [Bug 2895565]. Dropped bogosity

	* tests/io.test: which used the number of _written_ bytes or
	character to update the counters for the read bytes/characters.
	New test io-53.11. This is a forward port from the 8.5 branch.

3 files changed, 51 insertions, 10 deletions

diff --git a/ChangeLog b/ChangeLog
index a5fea35..7757b62 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2009-11-12  Andreas Kupries  <andreask@activestate.com>
+
+	* generic/tclIO.c (CopyData): [Bug 2895565]. Dropped bogosity
+	* tests/io.test: which used the number of _written_ bytes or
+	character to update the counters for the read bytes/characters.
+	New test io-53.11. This is a forward port from the 8.5 branch.
+
 2009-11-11  Don Porter  <dgp@users.sourceforge.net>
 
 	* generic/tclClock.c (TclClockInit):    Do not create [clock] support
diff --git a/generic/tclIO.c b/generic/tclIO.c
index e295c82..e8d231a 100644
--- a/generic/tclIO.c
+++ b/generic/tclIO.c
@@ -10,7 +10,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclIO.c,v 1.166 2009/11/10 23:50:17 ferrieux Exp $
+ * RCS: @(#) $Id: tclIO.c,v 1.167 2009/11/12 17:25:18 andreas_kupries Exp $
  */
 
 #include "tclInt.h"
@@ -9092,14 +9092,17 @@ CopyData(
 	    sizeb = DoWriteChars(outStatePtr->topChanPtr, buffer, sizeb);
 	}
 
-	if (inBinary || sameEncoding) {
-	    /*
-	     * Both read and write counted bytes.
-	     */
-
-	    size = sizeb;
-	} /* else: Read counted characters, write counted bytes, i.e.
-	   * size != sizeb */
+	/*
+	 * [Bug 2895565]. At this point 'size' still contains the number of
+	 * bytes or characters which have been read. We keep this to later to
+	 * update the totals and toRead information, see marker (UP) below. We
+	 * must not overwrite it with 'sizeb', which is the number of written
+	 * bytes or characters, and both EOL translation and encoding
+	 * conversion may have changed this number unpredictably in relation
+	 * to 'size' (It can be smaller or larger, in the latter case able to
+	 * drive toRead below -1, causing infinite looping). Completely
+	 * unsuitable for updating totals and toRead.
+	 */
 
 	if (sizeb < 0) {
 	writeError:
diff --git a/tests/io.test b/tests/io.test
index 0ab8909..1ad9f6e 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 1.93 2008/12/19 17:07:47 dgp Exp $
+# RCS: @(#) $Id: io.test,v 1.94 2009/11/12 17:25:18 andreas_kupries Exp $
 
 if {[catch {package require tcltest 2}]} {
     puts stderr "Skipping tests in [info script].  tcltest 2 required."
@@ -7126,6 +7126,37 @@ test io-53.10 {Bug 1350564, multi-directional fcopy} -setup {
     removeFile err
     catch {unset ::forever}
 } -result {AB BA}
+test io-53.11 {Bug 2895565} -setup {
+    set in [makeFile {} in]
+    set f [open $in w]
+    fconfigure $f -encoding utf-8 -translation binary
+    puts -nonewline $f [string repeat "Ho hum\n" 11]
+    close $f
+    set inChan [open $in r]
+    fconfigure $inChan -translation binary
+    set out [makeFile {} out]
+    set outChan [open $out w]
+    fconfigure $outChan -encoding cp1252 -translation crlf
+    proc CopyDone {bytes args} {
+	variable done
+	if {[llength $args]} {
+	    set done "Error: '[lindex $args 0]' after $bytes bytes copied"
+	} else {
+	    set done "$bytes bytes copied"
+	}
+    }
+} -body {
+    variable done
+    after 2000 [list set [namespace which -variable done] timeout]
+    fcopy $inChan $outChan -size 40 -command [namespace which CopyDone]
+    vwait [namespace which -variable done]
+    set done
+} -cleanup {
+    close $outChan
+    close $inChan
+    removeFile out
+    removeFile in
+} -result {40 bytes copied}
 
 test io-54.1 {Recursive channel events} {socket fileevent} {
     # This test checks to see if file events are delivered during recursive