Add new "git replace" command

diff --git a/sha1_file.c b/sha1_file.c
index 8fe135dc61908103cf2d7de700794843f83db057..9119b795bd2c39d91731f181a304e9575c0564f5 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -720,6 +720,8 @@ static int open_packed_git_1(struct packed_git *p)
                return error("packfile %s index unavailable", p->pack_name);
 
        p->pack_fd = open(p->pack_name, O_RDONLY);
+       while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
+               p->pack_fd = open(p->pack_name, O_RDONLY);
        if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
                return -1;
 
@@ -791,7 +793,7 @@ static int in_window(struct pack_window *win, off_t offset)
                && (offset + 20) <= (win_off + win->len);
 }
 
-unsigned char* use_pack(struct packed_git *p,
+unsigned char *use_pack(struct packed_git *p,
                struct pack_window **w_cursor,
                off_t offset,
                unsigned int *left)
@@ -937,6 +939,8 @@ static void prepare_packed_git_one(char *objdir, int local)
        sprintf(path, "%s/pack", objdir);
        len = strlen(path);
        dir = opendir(path);
+       while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
+               dir = opendir(path);
        if (!dir) {
                if (errno != ENOENT)
                        error("unable to open object pack directory: %s: %s",
@@ -2141,13 +2145,26 @@ static void *read_object(const unsigned char *sha1, enum object_type *type,
        return read_packed_sha1(sha1, type, size);
 }
 
-void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
-                    unsigned long *size)
+void *read_sha1_file_repl(const unsigned char *sha1,
+                         enum object_type *type,
+                         unsigned long *size,
+                         const unsigned char **replacement)
 {
-       void *data = read_object(sha1, type, size);
+       const unsigned char *repl = lookup_replace_object(sha1);
+       void *data = read_object(repl, type, size);
+
+       /* die if we replaced an object with one that does not exist */
+       if (!data && repl != sha1)
+               die("replacement %s not found for %s",
+                   sha1_to_hex(repl), sha1_to_hex(sha1));
+
        /* legacy behavior is to die on corrupted objects */
-       if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
-               die("object %s is corrupted", sha1_to_hex(sha1));
+       if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
+               die("object %s is corrupted", sha1_to_hex(repl));
+
+       if (replacement)
+               *replacement = repl;
+
        return data;
 }
 
@@ -2225,7 +2242,9 @@ int move_temp_to_file(const char *tmpfile, const char *filename)
 {
        int ret = 0;
 
-       if (link(tmpfile, filename))
+       if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
+               goto try_rename;
+       else if (link(tmpfile, filename))
                ret = errno;
 
        /*
@@ -2240,11 +2259,12 @@ int move_temp_to_file(const char *tmpfile, const char *filename)
         * left to unlink.
         */
        if (ret && ret != EEXIST) {
+       try_rename:
                if (!rename(tmpfile, filename))
                        goto out;
                ret = errno;
        }
-       unlink(tmpfile);
+       unlink_or_warn(tmpfile);
        if (ret) {
                if (ret != EEXIST) {
                        return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
@@ -2336,6 +2356,8 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 
        filename = sha1_file_name(sha1);
        fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
+       while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
+               fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
        if (fd < 0) {
                if (errno == EACCES)
                        return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());