doc/SubmittingPatches: show how to get a CLI commit summary

diff --git a/unpack-trees.c b/unpack-trees.c
index 129d49ff4517ae0f6c843a9f53c1617f3c2cb3ca..3a8ee19fe837aae6939c3a6b902f6b067dcde9e4 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -52,6 +52,41 @@ static const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
          ? ((o)->msgs[(type)])      \
          : (unpack_plumbing_errors[(type)]) )
 
+static const char *super_prefixed(const char *path)
+{
+       /*
+        * It is necessary and sufficient to have two static buffers
+        * here, as the return value of this function is fed to
+        * error() using the unpack_*_errors[] templates we see above.
+        */
+       static struct strbuf buf[2] = {STRBUF_INIT, STRBUF_INIT};
+       static int super_prefix_len = -1;
+       static unsigned idx = ARRAY_SIZE(buf) - 1;
+
+       if (super_prefix_len < 0) {
+               const char *super_prefix = get_super_prefix();
+               if (!super_prefix) {
+                       super_prefix_len = 0;
+               } else {
+                       int i;
+                       for (i = 0; i < ARRAY_SIZE(buf); i++)
+                               strbuf_addstr(&buf[i], super_prefix);
+                       super_prefix_len = buf[0].len;
+               }
+       }
+
+       if (!super_prefix_len)
+               return path;
+
+       if (++idx >= ARRAY_SIZE(buf))
+               idx = 0;
+
+       strbuf_setlen(&buf[idx], super_prefix_len);
+       strbuf_addstr(&buf[idx], path);
+
+       return buf[idx].buf;
+}
+
 void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
                                  const char *cmd)
 {
@@ -172,7 +207,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
                             const char *path)
 {
        if (!o->show_all_errors)
-               return error(ERRORMSG(o, e), path);
+               return error(ERRORMSG(o, e), super_prefixed(path));
 
        /*
         * Otherwise, insert in a list for future display by
@@ -196,7 +231,7 @@ static void display_error_msgs(struct unpack_trees_options *o)
                        something_displayed = 1;
                        for (i = 0; i < rejects->nr; i++)
                                strbuf_addf(&path, "\t%s\n", rejects->items[i].string);
-                       error(ERRORMSG(o, e), path.buf);
+                       error(ERRORMSG(o, e), super_prefixed(path.buf));
                        strbuf_release(&path);
                }
                string_list_clear(rejects, 0);
@@ -1925,7 +1960,9 @@ int bind_merge(const struct cache_entry * const *src,
                             o->merge_size);
        if (a && old)
                return o->gently ? -1 :
-                       error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
+                       error(ERRORMSG(o, ERROR_BIND_OVERLAP),
+                             super_prefixed(a->name),
+                             super_prefixed(old->name));
        if (!a)
                return keep_entry(old, o);
        else