push: add an advice on unqualified <dst> push

Add an advice to the recently improved error message added in
f8aae12034 ("push: allow unqualified dest refspecs to DWIM",
2008-04-23).

Now with advice.pushUnqualifiedRefName=true (on by default) we show a
hint about how to proceed:

    $ ./git-push avar v2.19.0^{commit}:newbranch -n
    error: The destination you provided is not a full refname (i.e.,
    starting with "refs/"). We tried to guess what you meant by:

    - Looking for a ref that matches 'newbranch' on the remote side.
    - Checking if the <src> being pushed ('v2.19.0^{commit}')
      is a ref in "refs/{heads,tags}/". If so we add a corresponding
      refs/{heads,tags}/ prefix on the remote side.

    Neither worked, so we gave up. You must fully qualify the ref.
    hint: The <src> part of the refspec is a commit object.
    hint: Did you mean to create a new branch by pushing to
    hint: 'v2.19.0^{commit}:refs/heads/newbranch'?
    error: failed to push some refs to 'git@github.com:avar/git.git'

When trying to push a tag, tree or a blob we suggest that perhaps the
user meant to push them to refs/tags/ instead.

The if/else duplication for all of OBJ_{COMMIT,TAG,TREE,BLOB} is
unfortunate, but is required to correctly mark the messages for
translation. See the discussion in
<87r2gxebsi.fsf@evledraar.gmail.com> about that.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/remote.c b/remote.c
index ba8abf4..f7477b8 100644
--- a/remote.c
+++ b/remote.c
@@ -13,6 +13,7 @@
 #include "mergesort.h"
 #include "argv-array.h"
 #include "commit-reach.h"
+#include "advice.h"
 
 enum map_direction { FROM_SRC, FROM_DST };
 
@@ -1008,6 +1009,9 @@ static int match_explicit_lhs(struct ref *src,
 static void show_push_unqualified_ref_name_error(const char *dst_value,
 						 const char *matched_src_name)
 {
+	struct object_id oid;
+	enum object_type type;
+
 	/*
 	 * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
 	 * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
@@ -1023,6 +1027,39 @@ static void show_push_unqualified_ref_name_error(const char *dst_value,
 		"\n"
 		"Neither worked, so we gave up. You must fully qualify the ref."),
 	      dst_value, matched_src_name);
+
+	if (!advice_push_unqualified_ref_name)
+		return;
+
+	if (get_oid(matched_src_name, &oid))
+		BUG("'%s' is not a valid object, "
+		    "match_explicit_lhs() should catch this!",
+		    matched_src_name);
+	type = oid_object_info(the_repository, &oid, NULL);
+	if (type == OBJ_COMMIT) {
+		advise(_("The <src> part of the refspec is a commit object.\n"
+			 "Did you mean to create a new branch by pushing to\n"
+			 "'%s:refs/heads/%s'?"),
+		       matched_src_name, dst_value);
+	} else if (type == OBJ_TAG) {
+		advise(_("The <src> part of the refspec is a tag object.\n"
+			 "Did you mean to create a new tag by pushing to\n"
+			 "'%s:refs/tags/%s'?"),
+		       matched_src_name, dst_value);
+	} else if (type == OBJ_TREE) {
+		advise(_("The <src> part of the refspec is a tree object.\n"
+			 "Did you mean to tag a new tree by pushing to\n"
+			 "'%s:refs/tags/%s'?"),
+		       matched_src_name, dst_value);
+	} else if (type == OBJ_BLOB) {
+		advise(_("The <src> part of the refspec is a blob object.\n"
+			 "Did you mean to tag a new blob by pushing to\n"
+			 "'%s:refs/tags/%s'?"),
+		       matched_src_name, dst_value);
+	} else {
+		BUG("'%s' should be commit/tag/tree/blob, is '%d'",
+		    matched_src_name, type);
+	}
 }
 
 static int match_explicit(struct ref *src, struct ref *dst,