write-tree is now willing to write empty tree

[git.git] / diff-cache.c

diff --git a/diff-cache.c b/diff-cache.c
index 3bd306c..7e87d28 100644 (file)
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -3,45 +3,81 @@
 
 static int cached_only = 0;
 static int generate_patch = 0;
+static int match_nonexisting = 0;
 static int line_termination = '\n';
 
 /* A file entry went away or appeared */
-static void show_file(const char *prefix, struct cache_entry *ce)
+static void show_file(const char *prefix, struct cache_entry *ce, unsigned char *sha1, unsigned int mode)
 {
        if (generate_patch)
-               diff_addremove(prefix[0], ntohl(ce->ce_mode),
-                              ce->sha1, ce->name, NULL);
+               diff_addremove(prefix[0], ntohl(mode), sha1, ce->name, NULL);
        else
-               printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(ce->ce_mode),
-                      sha1_to_hex(ce->sha1), ce->name,
-                      line_termination);
+               printf("%s%06o\tblob\t%s\t%s%c", prefix, ntohl(mode),
+                      sha1_to_hex(sha1), ce->name, line_termination);
 }
 
-static int show_modified(struct cache_entry *old, struct cache_entry *new)
+static int get_stat_data(struct cache_entry *ce, unsigned char **sha1p, unsigned int *modep)
 {
-       unsigned int mode = ntohl(new->ce_mode), oldmode;
-       unsigned char *sha1 = new->sha1;
-       unsigned char old_sha1_hex[60];
+       unsigned char *sha1 = ce->sha1;
+       unsigned int mode = ce->ce_mode;
 
        if (!cached_only) {
                static unsigned char no_sha1[20];
                int changed;
                struct stat st;
-               if (stat(new->name, &st) < 0) {
-                       show_file("-", old);
+               if (lstat(ce->name, &st) < 0) {
+                       if (errno == ENOENT && match_nonexisting) {
+                               *sha1p = sha1;
+                               *modep = mode;
+                               return 0;
+                       }
                        return -1;
                }
-               changed = cache_match_stat(new, &st);
+               changed = cache_match_stat(ce, &st);
                if (changed) {
-                       mode = st.st_mode;
+                       mode = create_ce_mode(st.st_mode);
                        sha1 = no_sha1;
                }
        }
 
-       oldmode = ntohl(old->ce_mode);
+       *sha1p = sha1;
+       *modep = mode;
+       return 0;
+}
+
+static void show_new_file(struct cache_entry *new)
+{
+       unsigned char *sha1;
+       unsigned int mode;
+
+       /* New file in the index: it might actually be different in the working copy */
+       if (get_stat_data(new, &sha1, &mode) < 0)
+               return;
+
+       show_file("+", new, sha1, mode);
+}
+
+static int show_modified(struct cache_entry *old,
+                        struct cache_entry *new,
+                        int report_missing)
+{
+       unsigned int mode, oldmode;
+       unsigned char *sha1;
+       unsigned char old_sha1_hex[60];
+
+       if (get_stat_data(new, &sha1, &mode) < 0) {
+               if (report_missing)
+                       show_file("-", old, old->sha1, old->ce_mode);
+               return -1;
+       }
+
+       oldmode = old->ce_mode;
        if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
                return 0;
 
+       mode = ntohl(mode);
+       oldmode = ntohl(oldmode);
+
        if (generate_patch)
                diff_change(oldmode, mode,
                            old->sha1, sha1, old->name, NULL);
@@ -64,19 +100,31 @@ static int diff_cache(struct cache_entry **ac, int entries)
                case 0:
                        /* No stage 1 entry? That means it's a new file */
                        if (!same) {
-                               show_file("+", ce);
+                               show_new_file(ce);
                                break;
                        }
                        /* Show difference between old and new */
-                       show_modified(ac[1], ce);
+                       show_modified(ac[1], ce, 1);
                        break;
                case 1:
                        /* No stage 3 (merge) entry? That means it's been deleted */
                        if (!same) {
-                               show_file("-", ce);
+                               show_file("-", ce, ce->sha1, ce->ce_mode);
                                break;
                        }
-                       /* Otherwise we fall through to the "unmerged" case */
+                       /* We come here with ce pointing at stage 1
+                        * (original tree) and ac[1] pointing at stage
+                        * 3 (unmerged).  show-modified with
+                        * report-mising set to false does not say the
+                        * file is deleted but reports true if work
+                        * tree does not have it, in which case we
+                        * fall through to report the unmerged state.
+                        * Otherwise, we show the differences between
+                        * the original tree and the work tree.
+                        */
+                       if (!cached_only && !show_modified(ce, ac[1], 0))
+                               break;
+                       /* fallthru */
                case 3:
                        if (generate_patch)
                                diff_unmerge(ce->name);
@@ -117,7 +165,7 @@ static void mark_merge_entries(void)
 }
 
 static char *diff_cache_usage =
-"diff-cache [-r] [-z] [-p] [--cached] <tree sha1>";
+"diff-cache [-r] [-z] [-p] [-i] [--cached] <tree sha1>";
 
 int main(int argc, char **argv)
 {
@@ -142,6 +190,10 @@ int main(int argc, char **argv)
                        line_termination = '\0';
                        continue;
                }
+               if (!strcmp(arg, "-m")) {
+                       match_nonexisting = 1;
+                       continue;
+               }
                if (!strcmp(arg, "--cached")) {
                        cached_only = 1;
                        continue;
@@ -149,12 +201,12 @@ int main(int argc, char **argv)
                usage(diff_cache_usage);
        }
 
-       if (argc != 2 || get_sha1_hex(argv[1], tree_sha1))
+       if (argc != 2 || get_sha1(argv[1], tree_sha1))
                usage(diff_cache_usage);
 
        mark_merge_entries();
 
-       tree = read_tree_with_tree_or_commit_sha1(tree_sha1, &size, 0);
+       tree = read_object_with_reference(tree_sha1, "tree", &size, 0);
        if (!tree)
                die("bad tree object %s", argv[1]);
        if (read_tree(tree, size, 1))