Use LF and allow comments in objects/info/alternates file.

Yes, using the same format for the file and the environment variable
was a big mistake.  This uses LF as the path separator, and allows
lines that begin with '#' to be comments.  ':' is no longer a separator
in objects/info/alternates file.

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

diff --git a/sha1_file.c b/sha1_file.c
index b6ebbc5..7766977 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -240,14 +240,21 @@ static struct alternate_object_database **alt_odb_tail;
  * SHA1, an extra slash for the first level indirection, and the
  * terminating NUL.
  */
-static void link_alt_odb_entries(const char *alt, const char *ep)
+static void link_alt_odb_entries(const char *alt, const char *ep, int sep)
 {
        const char *cp, *last;
        struct alternate_object_database *ent;
 
        last = alt;
-       do {
-               for (cp = last; cp < ep && *cp != ':'; cp++)
+       while (last < ep) {
+               cp = last;
+               if (cp < ep && *cp == '#') {
+                       while (cp < ep && *cp != sep)
+                               cp++;
+                       last = cp + 1;
+                       continue;
+               }
+               for ( ; cp < ep && *cp != sep; cp++)
                        ;
                if (last != cp) {
                        /* 43 = 40-byte + 2 '/' + terminating NUL */
@@ -264,16 +271,16 @@ static void link_alt_odb_entries(const char *alt, const char *ep)
                        ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
                        ent->base[entlen-1] = 0;
                }
-               while (cp < ep && *cp == ':')
+               while (cp < ep && *cp == sep)
                        cp++;
                last = cp;
-       } while (cp < ep);
+       }
 }
 
 void prepare_alt_odb(void)
 {
        char path[PATH_MAX];
-       char *map, *ep;
+       char *map;
        int fd;
        struct stat st;
        char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
@@ -282,7 +289,7 @@ void prepare_alt_odb(void)
        if (alt_odb_tail)
                return;
        alt_odb_tail = &alt_odb_list;
-       link_alt_odb_entries(alt, alt + strlen(alt));
+       link_alt_odb_entries(alt, alt + strlen(alt), ':');
 
        fd = open(path, O_RDONLY);
        if (fd < 0)
@@ -296,10 +303,7 @@ void prepare_alt_odb(void)
        if (map == MAP_FAILED)
                return;
 
-       /* Remove the trailing newline */
-       for (ep = map + st.st_size - 1; map < ep && ep[-1] == '\n'; ep--)
-               ;
-       link_alt_odb_entries(map, ep);
+       link_alt_odb_entries(map, map + st.st_size, '\n');
        munmap(map, st.st_size);
 }