Quote reference names while fetching with curl.

curl_escape ought to do this, but we should not let it quote
slashes (nobody said refs/tags cannot have subdirectories), so
we roll our own safer version.  With this, the last part of
git-clone from Martin's moodle repository that used to fail now
works, which reads:

 $ git-http-fetch -v -a -w 'tags/MOODLE_15_MERGED **INVALID**' \
   'tags/MOODLE_15_MERGED **INVALID**' \
   http://locke.catalyst.net.nz/git/moodle.git/

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/http-fetch.c b/http-fetch.c
index e537591..0aba891 100644 (file)
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -969,9 +969,54 @@ int fetch(unsigned char *sha1)
                     alt->base);
 }
 
+static inline int needs_quote(int ch)
+{
+       switch (ch) {
+       case '/': case '-': case '.':
+       case 'A'...'Z': case 'a'...'z': case '0'...'9':
+               return 0;
+       default:
+               return 1;
+       }
+}
+
+static inline int hex(int v)
+{
+       if (v < 10) return '0' + v;
+       else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+       const char *cp;
+       char *dp, *qref;
+       int len, baselen, ch;
+
+       baselen = strlen(base);
+       len = baselen + 6; /* "refs/" + NUL */
+       for (cp = ref; (ch = *cp) != 0; cp++, len++)
+               if (needs_quote(ch))
+                       len += 2; /* extra two hex plus replacement % */
+       qref = xmalloc(len);
+       memcpy(qref, base, baselen);
+       memcpy(qref + baselen, "refs/", 5);
+       for (cp = ref, dp = qref + baselen + 5; (ch = *cp) != 0; cp++) {
+               if (needs_quote(ch)) {
+                       *dp++ = '%';
+                       *dp++ = hex((ch >> 4) & 0xF);
+                       *dp++ = hex(ch & 0xF);
+               }
+               else
+                       *dp++ = ch;
+       }
+       *dp = 0;
+
+       return qref;
+}
+
 int fetch_ref(char *ref, unsigned char *sha1)
 {
-        char *url, *posn;
+        char *url;
         char hex[42];
         struct buffer buffer;
        char *base = alt->base;
@@ -981,13 +1026,7 @@ int fetch_ref(char *ref, unsigned char *sha1)
         buffer.buffer = hex;
         hex[41] = '\0';
         
-        url = xmalloc(strlen(base) + 6 + strlen(ref));
-        strcpy(url, base);
-        posn = url + strlen(base);
-        strcpy(posn, "refs/");
-        posn += 5;
-        strcpy(posn, ref);
-
+       url = quote_ref_url(base, ref);
        slot = get_active_slot();
        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);