Fixed the weird edge case.bug_3613609

2 files changed, 28 insertions, 12 deletions

diff --git a/generic/tclUtf.c b/generic/tclUtf.c
index a7a2091..f3d1758 100644
--- a/generic/tclUtf.c
+++ b/generic/tclUtf.c
@@ -1101,31 +1101,44 @@ Tcl_UtfNcasecmp(
     }
     return 0;
 }
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_UtfNcasecmp --
+ *
+ *	Compare UTF chars of string cs to string ct case insensitively.
+ *	Replacement for strcasecmp in Tcl core, in places where UTF-8 should
+ *	be handled.
+ *
+ * Results:
+ *	Return <0 if cs < ct, 0 if cs == ct, or >0 if cs > ct.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
 
-
-/* Replacement for strcasecmp in Tcl core, in places where UTF-8 should be handled. */
 int
 TclUtfCasecmp(
     CONST char *cs,		/* UTF string to compare to ct. */
     CONST char *ct)		/* UTF string cs is compared to. */
 {
-    Tcl_UniChar ch1, ch2;
-    int goOn;
-
-    do {
-
-	/* If *cs == '\0' or *ct == '\0', loop should end. */
-	goOn = *cs && *ct;
+    while (*cs && *ct) {
+	Tcl_UniChar ch1, ch2;
 
 	cs += TclUtfToUniChar(cs, &ch1);
 	ct += TclUtfToUniChar(ct, &ch2);
 	if (ch1 != ch2) {
 	    ch1 = Tcl_UniCharToLower(ch1);
 	    ch2 = Tcl_UniCharToLower(ch2);
-	    if (ch1 != ch2) break;
+	    if (ch1 != ch2) {
+		return ch1 - ch2;
+	    }
 	}
-    } while (goOn);
-    return (ch1 - ch2);
+    }
+    return UCHAR(*cs) - UCHAR(*ct);
 }
 
 
diff --git a/tests/cmdIL.test b/tests/cmdIL.test
index 192c10c..6fab269 100644
--- a/tests/cmdIL.test
+++ b/tests/cmdIL.test
@@ -400,6 +400,9 @@ test cmdIL-4.36 {SortCompare procedure, UTF-8 with -nocase option} {
 test cmdIL-4.37 {SortCompare procedure, UTF-8 with -nocase option} {
     scan [lsort -ascii -nocase [list a\u0000a a]] %c%c%c%c%c
 } {97 32 97 0 97}
+test cmdIL-4.38 {SortCompare procedure, UTF-8 with -nocase option} {
+    scan [lsort -ascii -nocase [list a a\u0000a]] %c%c%c%c%c
+} {97 32 97 0 97}
 
 test cmdIL-5.1 {lsort with list style index} {
     lsort -ascii -decreasing -index {0 1} {