Fix a number of issues and bugs with regsub():

Allow '\' to escape the next char.

Make '$$' be the same as '&': entire match
XXX: NB: Should we drop the sed(1) usage of '&' here, it means
XXX: a lot of backslashing in query string urls ?

Make $-digit work correctly.

Fixes ticket 249

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@2739 d4fa192b-c00b-0410-8231-f00ffab90ce4

diff --git a/varnish-cache/bin/varnishd/cache_vrt_re.c b/varnish-cache/bin/varnishd/cache_vrt_re.c
index 538e1a4b99e2757b43e9ef448b419ea522dc76db..884203261003cf1cc52cddaf4173edfbc7053cf4 100644 (file)
--- a/varnish-cache/bin/varnishd/cache_vrt_re.c
+++ b/varnish-cache/bin/varnishd/cache_vrt_re.c
@@ -109,7 +109,8 @@ VRT_regsub(const struct sess *sp, int all, const char *str, void *re, const char
        regmatch_t pm[10];
        regex_t *t;
        int i, l;
-       char *b, *p, *e;
+       txt res;
+       char *p;
        const char *s;
        unsigned u, x;
 
@@ -122,38 +123,31 @@ VRT_regsub(const struct sess *sp, int all, const char *str, void *re, const char
                return(str);
 
        u = WS_Reserve(sp->http->ws, 0);
-       e = p = b = sp->http->ws->f;
-       e += u;
+       res.e = res.b = p = sp->http->ws->f;
+       res.e += u;
 
        do {
                /* Copy prefix to match */
-               if (pm[0].rm_so > 0) {
-                       if (p + pm[0].rm_so < e)
-                               memcpy(p, str, pm[0].rm_so);
-                       p += pm[0].rm_so;
-               }
+               Tadd(&res, str, pm[0].rm_so);
 
                for (s = sub ; *s != '\0'; s++ ) {
-                       if (*s == '&') {
+                       if (*s == '\\') {
+                               if (res.b < res.e)
+                                       *res.b++ = *++s;
+                       } else if (*s == '&') {
+                               l = pm[0].rm_eo - pm[0].rm_so;
+                               Tadd(&res, str + pm[0].rm_so, l);
+                       } else if (*s == '$' && s[1] == '$') {
                                l = pm[0].rm_eo - pm[0].rm_so;
-                               if (l > 0) {
-                                       if (p + l < e)
-                                               memcpy(p, str + pm[0].rm_so, l);
-                                       p += l;
-                               }
+                               Tadd(&res, str + pm[0].rm_so, l);
+                               s++;
                        } else if (*s == '$' && isdigit(s[1])) {
-                               x = sub[1] - '0';
-                               sub++;
+                               x = digittoint(*++s);
                                l = pm[x].rm_eo - pm[x].rm_so;
-                               if (l > 0) {
-                                       if (p + l < e)
-                                               memcpy(p, str + pm[x].rm_so, l);
-                                       p += l;
-                               }
+                               Tadd(&res, str + pm[x].rm_so, l);
                        } else {
-                               if (p + 1 < e)
-                                       *p = *s;
-                               p++;
+                               if (res.b < res.e)
+                                       *res.b++ = *s;
                        }
                }
                str += pm[0].rm_eo;
@@ -163,19 +157,13 @@ VRT_regsub(const struct sess *sp, int all, const char *str, void *re, const char
        } while (i != REG_NOMATCH);
 
        /* Copy suffix to match */
-       l = strlen(str);
-       if (l > 0) {
-               if (p + l < e)
-                       memcpy(p, str, l);
-               p += l;
-       }
-       if (p + 1 < e)
-               *p++ = '\0';
-       xxxassert(p <= e);
-       if (p > e) {
+       l = strlen(str) + 1;
+       Tadd(&res, str, l);
+       if (res.b >= res.e) {
                WS_Release(sp->http->ws, 0);
                return (str);
        } 
-       WS_Release(sp->http->ws, p - b);
-       return (b);
+       Tcheck(res);
+       WS_Release(sp->http->ws, p - res.b);
+       return (p);
 }