ref_transaction_commit(): provide better error messages

diff --git a/log-tree.c b/log-tree.c
index 53bb52659b41c5a2fddc61af05a3a2ef90528b15..2c1ed0fa90170438e00a2eadbf74e15d89531613 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -172,6 +172,43 @@ static void show_children(struct rev_info *opt, struct commit *commit, int abbre
        }
 }
 
+/*
+ * Do we have HEAD in the output, and also the branch it points at?
+ * If so, find that decoration entry for that current branch.
+ */
+static const struct name_decoration *current_pointed_by_HEAD(const struct name_decoration *decoration)
+{
+       const struct name_decoration *list, *head = NULL;
+       const char *branch_name = NULL;
+       unsigned char unused[20];
+       int rru_flags;
+
+       /* First find HEAD */
+       for (list = decoration; list; list = list->next)
+               if (list->type == DECORATION_REF_HEAD) {
+                       head = list;
+                       break;
+               }
+       if (!head)
+               return NULL;
+
+       /* Now resolve and find the matching current branch */
+       branch_name = resolve_ref_unsafe("HEAD", 0, unused, &rru_flags);
+       if (!(rru_flags & REF_ISSYMREF))
+               return NULL;
+       if (!skip_prefix(branch_name, "refs/heads/", &branch_name))
+               return NULL;
+
+       /* OK, do we have that ref in the list? */
+       for (list = decoration; list; list = list->next)
+               if ((list->type == DECORATION_REF_LOCAL) &&
+                   !strcmp(branch_name, list->name)) {
+                       return list;
+               }
+
+       return NULL;
+}
+
 /*
  * The caller makes sure there is no funny color before calling.
  * format_decorations_extended makes sure the same after return.
@@ -184,6 +221,7 @@ void format_decorations_extended(struct strbuf *sb,
                        const char *suffix)
 {
        const struct name_decoration *decoration;
+       const struct name_decoration *current_and_HEAD;
        const char *color_commit =
                diff_get_color(use_color, DIFF_COMMIT);
        const char *color_reset =
@@ -192,16 +230,37 @@ void format_decorations_extended(struct strbuf *sb,
        decoration = get_name_decoration(&commit->object);
        if (!decoration)
                return;
+
+       current_and_HEAD = current_pointed_by_HEAD(decoration);
        while (decoration) {
-               strbuf_addstr(sb, color_commit);
-               strbuf_addstr(sb, prefix);
-               strbuf_addstr(sb, color_reset);
-               strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
-               if (decoration->type == DECORATION_REF_TAG)
-                       strbuf_addstr(sb, "tag: ");
-               strbuf_addstr(sb, decoration->name);
-               strbuf_addstr(sb, color_reset);
-               prefix = separator;
+               /*
+                * When both current and HEAD are there, only
+                * show HEAD->current where HEAD would have
+                * appeared, skipping the entry for current.
+                */
+               if (decoration != current_and_HEAD) {
+                       strbuf_addstr(sb, color_commit);
+                       strbuf_addstr(sb, prefix);
+                       strbuf_addstr(sb, color_reset);
+                       strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
+                       if (decoration->type == DECORATION_REF_TAG)
+                               strbuf_addstr(sb, "tag: ");
+
+                       strbuf_addstr(sb, decoration->name);
+
+                       if (current_and_HEAD &&
+                           decoration->type == DECORATION_REF_HEAD) {
+                               strbuf_addstr(sb, color_reset);
+                               strbuf_addstr(sb, color_commit);
+                               strbuf_addstr(sb, " -> ");
+                               strbuf_addstr(sb, color_reset);
+                               strbuf_addstr(sb, decorate_get_color(use_color, current_and_HEAD->type));
+                               strbuf_addstr(sb, current_and_HEAD->name);
+                       }
+                       strbuf_addstr(sb, color_reset);
+
+                       prefix = separator;
+               }
                decoration = decoration->next;
        }
        strbuf_addstr(sb, color_commit);