Merge branch 'jb/remote-rm'
[gitweb.git] / tree-diff.c
index 15fd665fb827bfa6ebc9254b5eab142e7d261718..26bdbdd2bfea5eab99b9f1c38936efe56f1ab45a 100644 (file)
@@ -3,6 +3,7 @@
  */
 #include "cache.h"
 #include "diff.h"
+#include "diffcore.h"
 #include "tree.h"
 
 static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
@@ -70,7 +71,8 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
  * Is a tree entry interesting given the pathspec we have?
  *
  * Return:
- *  - positive for yes
+ *  - 2 for "yes, and all subsequent entries will be"
+ *  - 1 for yes
  *  - zero for no
  *  - negative for "no, and no subsequent entries will be either"
  */
@@ -100,8 +102,11 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
                        if (strncmp(base, match, matchlen))
                                continue;
 
-                       /* The base is a subdirectory of a path which was specified. */
-                       return 1;
+                       /*
+                        * The base is a subdirectory of a path which
+                        * was specified, so all of them are interesting.
+                        */
+                       return 2;
                }
 
                /* Does the base match? */
@@ -173,8 +178,18 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
 /* A whole sub-tree went away or appeared */
 static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
 {
+       int all_interesting = 0;
        while (desc->size) {
-               int show = tree_entry_interesting(desc, base, baselen, opt);
+               int show;
+
+               if (all_interesting)
+                       show = 1;
+               else {
+                       show = tree_entry_interesting(desc, base, baselen,
+                                                     opt);
+                       if (show == 2)
+                               all_interesting = 1;
+               }
                if (show < 0)
                        break;
                if (show)
@@ -215,8 +230,17 @@ static void show_entry(struct diff_options *opt, const char *prefix, struct tree
 
 static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt)
 {
+       int all_interesting = 0;
        while (t->size) {
-               int show = tree_entry_interesting(t, base, baselen, opt);
+               int show;
+
+               if (all_interesting)
+                       show = 1;
+               else {
+                       show = tree_entry_interesting(t, base, baselen, opt);
+                       if (show == 2)
+                               all_interesting = 1;
+               }
                if (!show) {
                        update_tree_entry(t);
                        continue;
@@ -267,6 +291,78 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
        return 0;
 }
 
+/*
+ * Does it look like the resulting diff might be due to a rename?
+ *  - single entry
+ *  - not a valid previous file
+ */
+static inline int diff_might_be_rename(void)
+{
+       return diff_queued_diff.nr == 1 &&
+               !DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
+}
+
+static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
+{
+       struct diff_options diff_opts;
+       struct diff_queue_struct *q = &diff_queued_diff;
+       struct diff_filepair *choice;
+       const char *paths[1];
+       int i;
+
+       /* Remove the file creation entry from the diff queue, and remember it */
+       choice = q->queue[0];
+       q->nr = 0;
+
+       diff_setup(&diff_opts);
+       diff_opts.recursive = 1;
+       diff_opts.detect_rename = DIFF_DETECT_RENAME;
+       diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+       diff_opts.single_follow = opt->paths[0];
+       paths[0] = NULL;
+       diff_tree_setup_paths(paths, &diff_opts);
+       if (diff_setup_done(&diff_opts) < 0)
+               die("unable to set up diff options to follow renames");
+       diff_tree(t1, t2, base, &diff_opts);
+       diffcore_std(&diff_opts);
+
+       /* Go through the new set of filepairing, and see if we find a more interesting one */
+       for (i = 0; i < q->nr; i++) {
+               struct diff_filepair *p = q->queue[i];
+
+               /*
+                * Found a source? Not only do we use that for the new
+                * diff_queued_diff, we will also use that as the path in
+                * the future!
+                */
+               if ((p->status == 'R' || p->status == 'C') && !strcmp(p->two->path, opt->paths[0])) {
+                       /* Switch the file-pairs around */
+                       q->queue[i] = choice;
+                       choice = p;
+
+                       /* Update the path we use from now on.. */
+                       opt->paths[0] = xstrdup(p->one->path);
+                       diff_tree_setup_paths(opt->paths, opt);
+                       break;
+               }
+       }
+
+       /*
+        * Then, discard all the non-relevane file pairs...
+        */
+       for (i = 0; i < q->nr; i++) {
+               struct diff_filepair *p = q->queue[i];
+               diff_free_filepair(p);
+       }
+
+       /*
+        * .. and re-instate the one we want (which might be either the
+        * original one, or the rename/copy we found)
+        */
+       q->queue[0] = choice;
+       q->nr = 1;
+}
+
 int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
 {
        void *tree1, *tree2;
@@ -283,6 +379,11 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
        init_tree_desc(&t1, tree1, size1);
        init_tree_desc(&t2, tree2, size2);
        retval = diff_tree(&t1, &t2, base, opt);
+       if (opt->follow_renames && diff_might_be_rename()) {
+               init_tree_desc(&t1, tree1, size1);
+               init_tree_desc(&t2, tree2, size2);
+               try_to_follow_renames(&t1, &t2, base, opt);
+       }
        free(tree1);
        free(tree2);
        return retval;