git-apply: apply submodule changes

Apply "Subproject commit HEX" changes produced by git-diff.
As usual in the current git, only the superproject itself is actually
modified (possibly creating empty directories for new submodules).
Any checked-out submodule is left untouched and is not required to
be up-to-date.

With clean-ups from Junio C Hamano.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-apply.txt b/Documentation/git-apply.txt
index f03f661652814d0900f3564c1914b217dc465a01..4c7e3a2f7f5d542cd95059430f53143bba59fc7f 100644 (file)
--- a/Documentation/git-apply.txt
+++ b/Documentation/git-apply.txt
@@ -171,6 +171,20 @@ apply.whitespace::
        When no `--whitespace` flag is given from the command
        line, this configuration item is used as the default.
 
+Submodules
+----------
+If the patch contains any changes to submodules then gitlink:git-apply[1]
+treats these changes as follows.
+
+If --index is specified (explicitly or implicitly), then the submodule
+commits must match the index exactly for the patch to apply.  If any
+of the submodules are checked-out, then these check-outs are completely
+ignored, i.e., they are not required to be up-to-date or clean and they
+are not updated.
+
+If --index is not specified, then the submodule commits in the patch
+are ignored and only the absence of presence of the corresponding
+subdirectory is checked and (if possible) updated.
 
 Author
 ------

diff --git a/builtin-apply.c b/builtin-apply.c
index da270755a7b9ecafa3cb47d9f6947c6dc5b2531c..25b1447901d4085bdc5b554451c5e79b72cbae12 100644 (file)
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1984,6 +1984,25 @@ static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
        return 0;
 }
 
+static int read_file_or_gitlink(struct cache_entry *ce, char **buf_p,
+                               unsigned long *size_p)
+{
+       if (!ce)
+               return 0;
+
+       if (S_ISGITLINK(ntohl(ce->ce_mode))) {
+               *buf_p = xmalloc(100);
+               *size_p = snprintf(*buf_p, 100,
+                       "Subproject commit %s\n", sha1_to_hex(ce->sha1));
+       } else {
+               enum object_type type;
+               *buf_p = read_sha1_file(ce->sha1, &type, size_p);
+               if (!*buf_p)
+                       return -1;
+       }
+       return 0;
+}
+
 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
 {
        char *buf;
@@ -1994,22 +2013,32 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
        alloc = 0;
        buf = NULL;
        if (cached) {
-               if (ce) {
-                       enum object_type type;
-                       buf = read_sha1_file(ce->sha1, &type, &size);
-                       if (!buf)
+               if (read_file_or_gitlink(ce, &buf, &size))
+                       return error("read of %s failed", patch->old_name);
+               alloc = size;
+       } else if (patch->old_name) {
+               if (S_ISGITLINK(patch->old_mode)) {
+                       if (ce)
+                               read_file_or_gitlink(ce, &buf, &size);
+                       else {
+                               /*
+                                * There is no way to apply subproject
+                                * patch without looking at the index.
+                                */
+                               patch->fragments = NULL;
+                               size = 0;
+                       }
+               }
+               else {
+                       size = xsize_t(st->st_size);
+                       alloc = size + 8192;
+                       buf = xmalloc(alloc);
+                       if (read_old_data(st, patch->old_name,
+                                         &buf, &alloc, &size))
                                return error("read of %s failed",
                                             patch->old_name);
-                       alloc = size;
                }
        }
-       else if (patch->old_name) {
-               size = xsize_t(st->st_size);
-               alloc = size + 8192;
-               buf = xmalloc(alloc);
-               if (read_old_data(st, patch->old_name, &buf, &alloc, &size))
-                       return error("read of %s failed", patch->old_name);
-       }
 
        desc.size = size;
        desc.alloc = alloc;
@@ -2055,6 +2084,16 @@ static int check_to_create_blob(const char *new_name, int ok_if_exists)
        return 0;
 }
 
+static int verify_index_match(struct cache_entry *ce, struct stat *st)
+{
+       if (S_ISGITLINK(ntohl(ce->ce_mode))) {
+               if (!S_ISDIR(st->st_mode))
+                       return -1;
+               return 0;
+       }
+       return ce_match_stat(ce, st, 1);
+}
+
 static int check_patch(struct patch *patch, struct patch *prev_patch)
 {
        struct stat st;
@@ -2065,8 +2104,14 @@ static int check_patch(struct patch *patch, struct patch *prev_patch)
        int ok_if_exists;
 
        patch->rejected = 1; /* we will drop this after we succeed */
+
+       /*
+        * Make sure that we do not have local modifications from the
+        * index when we are looking at the index.  Also make sure
+        * we have the preimage file to be patched in the work tree,
+        * unless --cached, which tells git to apply only in the index.
+        */
        if (old_name) {
-               int changed = 0;
                int stat_ret = 0;
                unsigned st_mode = 0;
 
@@ -2096,15 +2141,12 @@ static int check_patch(struct patch *patch, struct patch *prev_patch)
                                    lstat(old_name, &st))
                                        return -1;
                        }
-                       if (!cached)
-                               changed = ce_match_stat(ce, &st, 1);
-                       if (changed)
+                       if (!cached && verify_index_match(ce, &st))
                                return error("%s: does not match index",
                                             old_name);
                        if (cached)
                                st_mode = ntohl(ce->ce_mode);
-               }
-               else if (stat_ret < 0)
+               } else if (stat_ret < 0)
                        return error("%s: %s", old_name, strerror(errno));
 
                if (!cached)
@@ -2354,7 +2396,11 @@ static void remove_file(struct patch *patch, int rmdir_empty)
                cache_tree_invalidate_path(active_cache_tree, patch->old_name);
        }
        if (!cached) {
-               if (!unlink(patch->old_name) && rmdir_empty) {
+               if (S_ISGITLINK(patch->old_mode)) {
+                       if (rmdir(patch->old_name))
+                               warning("unable to remove submodule %s",
+                                       patch->old_name);
+               } else if (!unlink(patch->old_name) && rmdir_empty) {
                        char *name = xstrdup(patch->old_name);
                        char *end = strrchr(name, '/');
                        while (end) {
@@ -2382,13 +2428,21 @@ static void add_index_file(const char *path, unsigned mode, void *buf, unsigned
        memcpy(ce->name, path, namelen);
        ce->ce_mode = create_ce_mode(mode);
        ce->ce_flags = htons(namelen);
-       if (!cached) {
-               if (lstat(path, &st) < 0)
-                       die("unable to stat newly created file %s", path);
-               fill_stat_cache_info(ce, &st);
+       if (S_ISGITLINK(mode)) {
+               const char *s = buf;
+
+               if (get_sha1_hex(s + strlen("Subproject commit "), ce->sha1))
+                       die("corrupt patch for subproject %s", path);
+       } else {
+               if (!cached) {
+                       if (lstat(path, &st) < 0)
+                               die("unable to stat newly created file %s",
+                                   path);
+                       fill_stat_cache_info(ce, &st);
+               }
+               if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
+                       die("unable to create backing store for newly created file %s", path);
        }
-       if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
-               die("unable to create backing store for newly created file %s", path);
        if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
                die("unable to add cache entry for %s", path);
 }
@@ -2398,6 +2452,13 @@ static int try_create_file(const char *path, unsigned int mode, const char *buf,
        int fd;
        char *nbuf;
 
+       if (S_ISGITLINK(mode)) {
+               struct stat st;
+               if (!lstat(path, &st) && S_ISDIR(st.st_mode))
+                       return 0;
+               return mkdir(path, 0777);
+       }
+
        if (has_symlinks && S_ISLNK(mode))
                /* Although buf:size is counted string, it also is NUL
                 * terminated.

diff --git a/t/t7400-submodule-basic.sh b/t/t7400-submodule-basic.sh
index e8ce7cdb833e3c0f45ffb52d85d7572839e3e34a..9d142ed649ef98adcbf7c6d158890c9f55370ef7 100755 (executable)
--- a/t/t7400-submodule-basic.sh
+++ b/t/t7400-submodule-basic.sh
@@ -175,4 +175,21 @@ test_expect_success 'checkout superproject with subproject already present' '
        git-checkout master
 '
 
+test_expect_success 'apply submodule diff' '
+       git branch second &&
+       (
+               cd lib &&
+               echo s >s &&
+               git add s &&
+               git commit -m "change subproject"
+       ) &&
+       git update-index --add lib &&
+       git-commit -m "change lib" &&
+       git-format-patch -1 --stdout >P.diff &&
+       git checkout second &&
+       git apply --index P.diff &&
+       D=$(git diff --cached master) &&
+       test -z "$D"
+'
+
 test_done