gawk: sub_common has multi-byte aware bug

[KIMURA Koichi]

Hi,

A certain user faced bug of sub builtin function and report to me.
Then I investigated the bug.

reproduce script is here.

BEGIN {
        str = "type=\"directory\" version=\"1.0\""
        #print "BEGIN:", str

        while (str) {
                sub(/^[^=]*/, "", str);
                s = substr(str, 2)
                print s
                sub(/^="[^"]*"/, "", str)
                sub(/^[ \t]*/, "", str)
        }
}

and sample result is here (on GNU/Linux Fedora core 3)

address@hidden gawk-3.1.5]$ LC_ALL=C ./gawk -f subbug.awk
"directory" version="1.0"
"1.0"
address@hidden gawk-3.1.5]$ LC_ALL=en_US.UTF-8 ./gawk -f subbug.awk
"directory" version="1.0"
"dire
address@hidden gawk-3.1.5]$

In my investigation, this bug is cause by don't release wide-string when
sub is executed.

patch is here.

--- builtin.c.orig      2005-07-27 03:07:43.000000000 +0900
+++ builtin.c   2006-02-26 02:07:52.000000000 +0900
@@ -2463,6 +2468,15 @@ sub_common(NODE *tree, long how_many, in
        t->stptr = buf;
        t->stlen = textlen;

+#ifdef MBS_SUPPORT
+    if (t->flags & WSTRCUR) {
+        if (t->wstptr != NULL)
+            free(t->wstptr);
+        t->wstptr = NULL;
+        t->wstlen = 0;
+        t->flags &= ~WSTRCUR;
+    }
+#endif
        free_temp(s);
        if (matches > 0 && lhs) {
                if (priv) {


-- 
KIMURA Koichi