* generic/tclUtil.c: Corrected [Bug 411825] and other bugs in

        TclNeedSpace() where non-breaking space (\u00A0) and backslash-escaped
        spaces were handled incorrectly.
        * tests/util.test:      Added new tests util-8.[2-6].

3 files changed, 61 insertions, 28 deletions

diff --git a/ChangeLog b/ChangeLog
index dc84a3b..4af48f3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -28,8 +28,10 @@
 
 2003-08-27  Don Porter  <dgp@users.sourceforge.net>
 
-	* tests/util.test: Added new tests for remaining TclNeedSpace()
-	bugs discussed in [Bug 411825].
+        * generic/tclUtil.c:    Corrected [Bug 411825] and other bugs in
+        TclNeedSpace() where non-breaking space (\u00A0) and backslash-escaped
+        spaces were handled incorrectly.  
+        * tests/util.test:      Added new tests util-8.[2-6].
 
 2003-08-26  David Gravereaux <davygrvy@pobox.com>
 
diff --git a/generic/tclUtil.c b/generic/tclUtil.c
index fd58235..d939496 100644
--- a/generic/tclUtil.c
+++ b/generic/tclUtil.c
@@ -11,7 +11,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- *  RCS: @(#) $Id: tclUtil.c,v 1.40 2003/08/27 19:55:50 dgp Exp $
+ *  RCS: @(#) $Id: tclUtil.c,v 1.41 2003/08/27 20:29:36 dgp Exp $
  */
 
 #include "tclInt.h"
@@ -2001,42 +2001,53 @@ TclNeedSpace(start, end)
     CONST char *end;		/* End of string (place where space will
 				 * be added, if appropriate). */
 {
-    Tcl_UniChar ch;
-
     /*
      * A space is needed unless either
      * (a) we're at the start of the string, or
-     * (b) the trailing characters of the string consist of one or more
-     *     open curly braces preceded by a space or extending back to
-     *     the beginning of the string.
-     * (c) the trailing characters of the string consist of a space
-     *	   preceded by a character other than backslash.
      */
-
     if (end == start) {
 	return 0;
     }
+
+    /*
+     * (b) we're at the start of a nested list-element, quoted with an
+     *     open curly brace; we can be nested arbitrarily deep, so long
+     *     as the first curly brace starts an element, so backtrack over
+     *     open curly braces that are trailing characters of the string; and
+     */
+
     end = Tcl_UtfPrev(end, start);
-    if (*end != '{') {
-	Tcl_UtfToUniChar(end, &ch);
-	/*
-	 * Direct char comparison on next line is safe as it is with
-	 * a character in the ASCII subset, and so single-byte in UTF8.
-	 */
-	if (Tcl_UniCharIsSpace(ch) && ((end == start) || (end[-1] != '\\'))) {
-	    return 0;
-	}
-	return 1;
-    }
-    do {
+    while (*end == '{') {
 	if (end == start) {
 	    return 0;
 	}
 	end = Tcl_UtfPrev(end, start);
-    } while (*end == '{');
-    Tcl_UtfToUniChar(end, &ch);
-    if (Tcl_UniCharIsSpace(ch)) {
-	return 0;
+    }
+
+    /*
+     * (c) the trailing character of the string is already a list-element
+     *     separator (according to TclFindElement); that is, one of these
+     *     characters:
+     *     	\u0009	\t	TAB
+     *     	\u000A	\n	NEWLINE
+     *     	\u000B	\v	VERTICAL TAB
+     *     	\u000C	\f	FORM FEED
+     *     	\u000D	\r	CARRIAGE RETURN
+     *     	\u0020		SPACE
+     *     with the condition that the penultimate character is not a
+     *     backslash.
+     */
+
+    switch (*end) {
+	case ' ':
+        case '\f':
+        case '\n':
+        case '\r':
+        case '\t':
+        case '\v':
+	    if ((end == start) || (end[-1] != '\\')) {
+		return 0;
+	    }
     }
     return 1;
 }
diff --git a/tests/util.test b/tests/util.test
index ddba3e4..6c4db29 100644
--- a/tests/util.test
+++ b/tests/util.test
@@ -7,7 +7,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: util.test,v 1.12 2003/08/27 17:57:03 dgp Exp $
+# RCS: @(#) $Id: util.test,v 1.13 2003/08/27 20:29:36 dgp Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest
@@ -375,6 +375,26 @@ test util-8.4 {TclNeedSpace - correct UTF8 handling} testdstring {
     testdstring element foo
     llength [testdstring get]
 } 2
+test util-8.5 {TclNeedSpace - correct UTF8 handling} testdstring {
+    # Note that in this test TclNeedSpace actually gets it wrong,
+    # claiming we need a space when we really do not.  Extra space
+    # between list elements is harmless though, and better to have
+    # extra space in really weird string reps of lists, than to
+    # invest the effort required to make TclNeedSpace foolproof.
+    testdstring free
+    testdstring append {\\ } -1
+    testdstring element foo
+    list [llength [testdstring get]] [string length [testdstring get]]
+} {2 7}
+test util-8.6 {TclNeedSpace - correct UTF8 handling} testdstring {
+    # Another example of TclNeedSpace harmlessly getting it wrong.
+    testdstring free
+    testdstring append {\\ } -1
+    testdstring append \{ -1
+    testdstring element foo
+    testdstring append \} -1
+    list [llength [testdstring get]] [string length [testdstring get]]
+} {2 9}
 
 # cleanup
 ::tcltest::cleanupTests