http-fetch: fix alternates handling.

[git.git] / http-fetch.c

diff --git a/http-fetch.c b/http-fetch.c
index de5fc44e660e3eb6f52191dd0983744447a2fe46..259292d4de4959d29abad60f0c9cbd55e4b9b6d3 100644 (file)
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -559,9 +559,36 @@ static void process_alternates_response(void *callback_data)
                        char *target = NULL;
                        char *path;
                        if (data[i] == '/') {
-                               serverlen = strchr(base + 8, '/') - base;
-                               okay = 1;
+                               /* This counts
+                                * http://git.host/pub/scm/linux.git/
+                                * -----------here^
+                                * so memcpy(dst, base, serverlen) will
+                                * copy up to "...git.host".
+                                */
+                               const char *colon_ss = strstr(base,"://");
+                               if (colon_ss) {
+                                       serverlen = (strchr(colon_ss + 3, '/')
+                                                    - base);
+                                       okay = 1;
+                               }
                        } else if (!memcmp(data + i, "../", 3)) {
+                               /* Relative URL; chop the corresponding
+                                * number of subpath from base (and ../
+                                * from data), and concatenate the result.
+                                *
+                                * The code first drops ../ from data, and
+                                * then drops one ../ from data and one path
+                                * from base.  IOW, one extra ../ is dropped
+                                * from data than path is dropped from base.
+                                *
+                                * This is not wrong.  The alternate in
+                                *     http://git.host/pub/scm/linux.git/
+                                * to borrow from
+                                *     http://git.host/pub/scm/linus.git/
+                                * is ../../linus.git/objects/.  You need
+                                * two ../../ to borrow from your direct
+                                * neighbour.
+                                */
                                i += 3;
                                serverlen = strlen(base);
                                while (i + 2 < posn &&
@@ -583,11 +610,13 @@ static void process_alternates_response(void *callback_data)
                                        okay = 1;
                                }
                        }
-                       /* skip 'objects' at end */
+                       /* skip "objects\n" at end */
                        if (okay) {
                                target = xmalloc(serverlen + posn - i - 6);
-                               strlcpy(target, base, serverlen);
-                               strlcpy(target + serverlen, data + i, posn - i - 6);
+                               memcpy(target, base, serverlen);
+                               memcpy(target + serverlen, data + i,
+                                      posn - i - 7);
+                               target[serverlen + posn - i - 7] = 0;
                                if (get_verbosely)
                                        fprintf(stderr,
                                                "Also look at %s\n", target);