[PATCH] allow merging any committish

diff --git a/sha1_file.c b/sha1_file.c
index 82a01887c261676eb39fe72b108bfa56041d71f5..fa22e9c71a0360ad5c3a865e0d6b3b49ba97e064 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -184,8 +184,8 @@ static struct alternate_object_database **alt_odb_tail;
  * alternate_object_database.  The elements on this list come from
  * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
  * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
- * whose contents is exactly in the same format as that environment
- * variable.  Its base points at a statically allocated buffer that
+ * whose contents is similar to that environment variable but can be
+ * LF separated.  Its base points at a statically allocated buffer that
  * contains "/the/directory/corresponding/to/.git/objects/...", while
  * its name points just after the slash at the end of ".git/objects/"
  * in the example above, and has enough space to hold 40-byte hex
@@ -197,6 +197,7 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
 {
        const char *cp, *last;
        struct alternate_object_database *ent;
+       const char *objdir = get_object_directory();
        int base_len = -1;
 
        last = alt;
@@ -211,6 +212,7 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
                for ( ; cp < ep && *cp != sep; cp++)
                        ;
                if (last != cp) {
+                       struct alternate_object_database *alt;
                        /* 43 = 40-byte + 2 '/' + terminating NUL */
                        int pfxlen = cp - last;
                        int entlen = pfxlen + 43;
@@ -223,9 +225,7 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
                                pfxlen += base_len;
                        }
                        ent = xmalloc(sizeof(*ent) + entlen);
-                       *alt_odb_tail = ent;
-                       alt_odb_tail = &(ent->next);
-                       ent->next = NULL;
+
                        if (*last != '/' && relative_base) {
                                memcpy(ent->base, relative_base, base_len - 1);
                                ent->base[base_len - 1] = '/';
@@ -237,6 +237,22 @@ static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
                        ent->name = ent->base + pfxlen + 1;
                        ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
                        ent->base[entlen-1] = 0;
+
+                       /* Prevent the common mistake of listing the same
+                        * thing twice, or object directory itself.
+                        */
+                       for (alt = alt_odb_list; alt; alt = alt->next)
+                               if (!memcmp(ent->base, alt->base, pfxlen))
+                                       goto bad;
+                       if (!memcmp(ent->base, objdir, pfxlen)) {
+                       bad:
+                               free(ent);
+                       }
+                       else {
+                               *alt_odb_tail = ent;
+                               alt_odb_tail = &(ent->next);
+                               ent->next = NULL;
+                       }
                }
                while (cp < ep && *cp == sep)
                        cp++;
@@ -531,8 +547,9 @@ void prepare_packed_git(void)
        prepare_packed_git_one(get_object_directory(), 1);
        prepare_alt_odb();
        for (alt = alt_odb_list; alt; alt = alt->next) {
-               alt->name[0] = 0;
+               alt->name[-1] = 0;
                prepare_packed_git_one(alt->base, 0);
+               alt->name[-1] = '/';
        }
        run_once = 1;
 }
@@ -1511,6 +1528,40 @@ int has_sha1_file(const unsigned char *sha1)
        return find_sha1_file(sha1, &st) ? 1 : 0;
 }
 
+int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
+{
+       unsigned long size = 4096;
+       char *buf = malloc(size);
+       int iret, ret;
+       unsigned long off = 0;
+       unsigned char hdr[50];
+       int hdrlen;
+       do {
+               iret = read(fd, buf + off, size - off);
+               if (iret > 0) {
+                       off += iret;
+                       if (off == size) {
+                               size *= 2;
+                               buf = realloc(buf, size);
+                       }
+               }
+       } while (iret > 0);
+       if (iret < 0) {
+               free(buf);
+               return -1;
+       }
+       if (!type)
+               type = "blob";
+       if (write_object)
+               ret = write_sha1_file(buf, off, type, sha1);
+       else {
+               write_sha1_file_prepare(buf, off, type, sha1, hdr, &hdrlen);
+               ret = 0;
+       }
+       free(buf);
+       return ret;
+}
+
 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
 {
        unsigned long size = st->st_size;