* 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.

1 files changed, 14 insertions, 3 deletions

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;
 	}
     }