Implemented the URL regex replace mechanism.

diff --git a/lib/regex.c b/lib/regex.c
index 31a13845d500d16d03d38579ee635cab28d65d3f..524591ea03a3d5b496a63d1692c597263fba925d 100644 (file)
--- a/lib/regex.c
+++ b/lib/regex.c
@@ -16,6 +16,7 @@
 struct regex {
   struct re_pattern_buffer buf;
   struct re_registers regs;            /* Must not change between re_match() calls */
+  int len_cache;
 };
 
 regex *
@@ -24,7 +25,7 @@ rx_compile(byte *p)
   regex *r = xmalloc(sizeof(regex));
   const char *msg;
 
-  bzero(r, sizeof(*r));
+  bzero(r, sizeof(struct regex));
   r->buf.buffer = xmalloc(INITIAL_MEM);
   r->buf.allocated = INITIAL_MEM;
   msg = re_compile_pattern(p, strlen(p), &r->buf);
@@ -45,6 +46,7 @@ rx_match(regex *r, byte *s)
 {
   uns len = strlen(s);
 
+  r->len_cache = len;
   if (re_match(&r->buf, s, len, 0, &r->regs) < 0)
     return 0;
   if (r->regs.start[0] || r->regs.end[0] != len) /* XXX: Why regex doesn't enforce implicit "^...$" ? */
@@ -68,13 +70,18 @@ rx_subst(regex *r, byte *by, byte *src, byte *dest, uns destlen)
          if (*by >= '0' && *by <= '9') /* \0 gets replaced by entire pattern */
            {
              int j = *by++ - '0';
-             byte *s = src + r->regs.start[j];
-             int i = r->regs.end[j] - r->regs.start[j];
-             if (dest + i >= end)
-               return -1;
-             memcpy(dest, s, i);
-             dest += i;
-             continue;
+             if (j < r->regs.num_regs)
+               {
+                 byte *s = src + r->regs.start[j];
+                 uns i = r->regs.end[j] - r->regs.start[j];
+                 if (r->regs.start[j] > r->len_cache || r->regs.end[j] > r->len_cache)
+                   return -1;
+                 if (dest + i >= end)
+                   return -1;
+                 memcpy(dest, s, i);
+                 dest += i;
+                 continue;
+               }
            }
        }
       if (dest < end)