Fix a concat bug

If a string ended in backslash-space, the trailing space was lost.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

2 files changed, 39 insertions, 1 deletions

diff --git a/jim.c b/jim.c
index 0ed2c03..41f7666 100644
--- a/jim.c
+++ b/jim.c
@@ -5954,18 +5954,24 @@ Jim_Obj *Jim_ConcatObj(Jim_Interp *interp, int objc, Jim_Obj *const *objv)
         }
         if (objc)
             len += objc - 1;
-        /* Create the string rep, and a stinrg object holding it. */
+        /* Create the string rep, and a string object holding it. */
         p = bytes = Jim_Alloc(len + 1);
         for (i = 0; i < objc; i++) {
             const char *s = Jim_GetString(objv[i], &objLen);
 
+            /* Remove leading space */
             while (objLen && (*s == ' ' || *s == '\t' || *s == '\n')) {
                 s++;
                 objLen--;
                 len--;
             }
+            /* And trailing space */
             while (objLen && (s[objLen - 1] == ' ' ||
                     s[objLen - 1] == '\n' || s[objLen - 1] == '\t')) {
+                /* Handle trailing backslash-space case */
+                if (objLen > 1 && s[objLen - 2] == '\\') {
+                    break;
+                }
                 objLen--;
                 len--;
             }
diff --git a/tests/concat.test b/tests/concat.test
index 65d6e1b..7f961a8 100644
--- a/tests/concat.test
+++ b/tests/concat.test
@@ -30,3 +30,35 @@ test concat-4.2 {pruning off extra white space} {
 test concat-4.3 {pruning off extra white space sets length correctly} {
     llength [concat { {{a}} }]
 } 1
+
+test concat-5.1 {Tcl_ScanCountedElement procedure - don't leave unmatched braces} {
+    # This test checks for a very tricky feature.  Any list element
+    # generated with Tcl_ScanCountedElement and Tcl_ConvertElement must
+    # have the property that it can be enclosing in curly braces to make
+    # an embedded sub-list.  If this property doesn't hold, then
+    # Tcl_DStringStartSublist doesn't work.
+
+    set x {}
+    lappend x " \\\{ \\"
+    concat $x [llength "{$x}"]
+} {\ \\\{\ \\ 1}
+
+test concat-6.1 {Tcl_ConcatObj - backslash-space at end of argument} {
+    concat a {b\ } c
+} {a b\  c}
+test concat-6.2 {Tcl_ConcatObj - backslash-space at end of argument} {
+    concat a {b\   } c
+} {a b\  c}
+test concat-6.3 {Tcl_ConcatObj - backslash-space at end of argument} {
+    concat a {b\\   } c
+} {a b\\  c}
+test concat-6.4 {Tcl_ConcatObj - backslash-space at end of argument} {
+    concat a {b } c
+} {a b c}
+test concat-6.5 {Tcl_ConcatObj - backslash-space at end of argument} {
+    concat a { } c
+} {a c}
+test concat-6.6 {Tcl_ConcatObj - utf-8 sequence with "whitespace" char} {
+    # Check for Bug #227512.  If this violates C isspace, then it returns \xc3.
+    concat \xe0
+} \xe0