git-apply: allow operating in sparsely populated working tree.

This patch teaches 'git-apply --index' to automatically check
out a file being patched.  This happens only when the working
tree does not have it checked out.

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

diff --git a/apply.c b/apply.c
index f886272..79c5d8a 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -676,7 +676,10 @@ static int parse_fragment(char *line, unsigned long size, struct patch *patch, s
                 /* We allow "\ No newline at end of file". Depending
                  * on locale settings when the patch was produced we
                  * don't know what this line looks like. The only
-                 * thing we do know is that it begins with "\ ". */
+                 * thing we do know is that it begins with "\ ".
+                * Checking for 12 is just for sanity check -- any
+                * l10n of "\ No newline..." is at least that long.
+                */
                case '\\':
                        if (len < 12 || memcmp(line, "\\ ", 2))
                                return -1;
@@ -1030,17 +1033,39 @@ static int check_patch(struct patch *patch)
 
        if (old_name) {
                int changed;
+               int stat_ret = lstat(old_name, &st);
 
-               if (lstat(old_name, &st) < 0)
-                       return error("%s: %s", old_name, strerror(errno));
                if (check_index) {
                        int pos = cache_name_pos(old_name, strlen(old_name));
                        if (pos < 0)
-                               return error("%s: does not exist in index", old_name);
+                               return error("%s: does not exist in index",
+                                            old_name);
+                       if (stat_ret < 0) {
+                               struct checkout costate;
+                               if (errno != ENOENT)
+                                       return error("%s: %s", old_name,
+                                                    strerror(errno));
+                               /* checkout */
+                               costate.base_dir = "";
+                               costate.base_dir_len = 0;
+                               costate.force = 0;
+                               costate.quiet = 0;
+                               costate.not_new = 0;
+                               costate.refresh_cache = 1;
+                               if (checkout_entry(active_cache[pos],
+                                                  &costate) ||
+                                   lstat(old_name, &st))
+                                       return -1;
+                       }
+
                        changed = ce_match_stat(active_cache[pos], &st);
                        if (changed)
-                               return error("%s: does not match index", old_name);
+                               return error("%s: does not match index",
+                                            old_name);
                }
+               else if (stat_ret < 0)
+                       return error("%s: %s", old_name, strerror(errno));
+
                if (patch->is_new < 0)
                        patch->is_new = 0;
                st.st_mode = ntohl(create_ce_mode(st.st_mode));