From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.1 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 6856B20958 for ; Wed, 29 Mar 2017 14:39:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752315AbdC2Ojg (ORCPT ); Wed, 29 Mar 2017 10:39:36 -0400 Received: from mout.kundenserver.de ([212.227.126.131]:54124 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501AbdC2Oje (ORCPT ); Wed, 29 Mar 2017 10:39:34 -0400 Received: from localhost ([130.75.46.4]) by mrelayeu.kundenserver.de (mreue001 [212.227.15.167]) with ESMTPSA (Nemesis) id 0M5lMH-1bvNvr1jk9-00xuTs; Wed, 29 Mar 2017 16:39:26 +0200 From: Michael J Gruber To: git@vger.kernel.org Cc: Junio C Hamano , Lars Schneider , Luke Diamand Subject: [PATCH v2 2/3] name-rev: favor describing with tags and use committer date to tiebreak Date: Wed, 29 Mar 2017 16:39:16 +0200 Message-Id: <516eccf0ff0df009d915c0ff2aa1a3d61ef63273.1490798142.git.git@grubix.eu> X-Mailer: git-send-email 2.12.2.712.gba4c48c431 In-Reply-To: References: In-Reply-To: References: X-Provags-ID: V03:K0:gPjTanivVXis4GqaHKCvaO6RbwmmvsrBnmyX4m2ZrTj8PbiXJ8M YU0bs9PFl61yGsL02uhiph1TXwV/OMBBobOq0NlNNU5kWlhXoKqH8UjfLWBI+ivHb64hg87 JdJeEM6/SsvEkBEhZz4ZHQ+7pVXVd3MLUxSeCvXMANX9Yf6uUdftvObzFvZIFkw+hcjK8dC 1pjF9OeJmir6vgw+NXXLA== X-UI-Out-Filterresults: notjunk:1;V01:K0:mE8bebZ1GwA=:WLCWLa1OPyt3XRlf3fc66g vuP9dDcAdMAmwU3EuONcxHTw1POIhZuLzKGoliOqYNsA9jlcoUJEcdr7sxZnXYy3f4Q0Oihx1 eyZUFToNWhmGha440fUbv07Gftk6AxZnNE9uZdqHMUu8KkkrnF/zQzm0b67LTy8pMTrGj1nF6 K2GrsLcCwoMFFuuMRtFwCrtWj3WwsCpygl+mEawPEW7BxBgGvUnIY/0eGbUuU/wrLl+v07G1x 46pD/xMsk2pfSioFkHGY469tAH6qJTDqtSjVwn09tEXD5zBOJytaI+QnCcoynp8nZNU1cenDN EnURxWu8Jt7l/3vr+YknFcOU7UpHKLIKh7V7phe+nw5U5dyqvCRPFwP8v0nQcKm9gLRIHIohy 0ypSOlDCUJIdZHXkl0iaOhSEcIA8z97VJCUODF9CKBnjSF7bLzOtQLh7tkqJ98CoRgvOalbPe VKyR7qpRG5qpUE1rzIDshnUz77AIEwKbabRUB7UKbHzPOrV/xlFviFBum26Hhx5wTEQVFZOeu /y4IwuSv2zi0J2Qes1XiYVMGvmfzdKUEYE6zaY/5NP2elIW6wGgZrdwW8cu7xbXYmVikPh1bK i21hgAeY9LOW5fCUqsLz99tSrJPlhrS3J3uaYM391x144tKNwYSWGPT8v8BxggpXt5M0Ql6n4 +HZHSdiq5rDCtJds/ZPqTZWH6KJIwoGtObHBM+H1pW799S1pshII83cJpXL8mgnJLEfY= Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Junio C Hamano "git name-rev" assigned a phony "far in the future" date to tips of refs that are not pointing at tag objects, and favored names based on a ref with the oldest date. This made it almost impossible for an unannotated tags and branches to be counted as a viable base, which was especially problematic when the command is run with the "--tags" option. If an unannotated tag that points at an ancient commit and an annotated tag that points at a much newer commit reaches the commit that is being named, the old unannotated tag was ignored. Update the "taggerdate" field of the rev-name structure, which is initialized from the tip of ref, to have the committer date if the object at the tip of ref is a commit, not a tag, so that we can optionally take it into account when doing "is this name better?" comparison logic. When "name-rev" is run without the "--tags" option, the general expectation is still to name the commit based on a tag if possible, but use non-tag refs as fallback, and tiebreak among these non-tag refs by favoring names with shorter hops from the tip. The use of a phony "far in the future" date in the original code was an effective way to ensure this expectation is held: a non-tag tip gets the same "far in the future" timestamp, giving precedence to tags, and among non-tag tips, names with shorter hops are preferred over longer hops, without taking the "taggerdate" into account. As we are taking over the "taggerdate" field to store the committer date for tips with commits: (1) keep the original logic when comparing names based on two refs both of which are from refs/tags/; (2) favoring a name based on a ref in refs/tags/ hierarchy over a ref outside the hierarchy; (3) between two names based on a ref both outside refs/tags/, give precedence to a name with shorter hops and use "taggerdate" only to tie-break. A change to t4202 is a natural consequence. The test creates a commit on a branch "side" and points at it with an unannotated tag "refs/tags/side-2". The original code couldn't decide which one to favor at all, and gave a name based on a branch (simply because refs/heads/side sorts earlier than refs/tags/side-2). Because the updated logic is taught to favor refs in refs/tags/ hierarchy, the the test is updated to expect to see tags/side-2 instead. Signed-off-by: Junio C Hamano --- * I am sure others can add better heurisitics in is_better_name() for comparing names based on non-tag refs, and I do not mind people disagreeing with the logic that this patch happens to implement. This is done primarily to illustrate the value of using a separate helper function is_better_name() instead of open-coding the selection logic in name_rev() function. Signed-off-by: Michael J Gruber --- builtin/name-rev.c | 53 ++++++++++++++++++++++++++++++++++++++++++++--------- t/t4202-log.sh | 2 +- 2 files changed, 45 insertions(+), 10 deletions(-) diff --git a/builtin/name-rev.c b/builtin/name-rev.c index 7890f826ce..bf7ed015ae 100644 --- a/builtin/name-rev.c +++ b/builtin/name-rev.c @@ -13,6 +13,7 @@ typedef struct rev_name { unsigned long taggerdate; int generation; int distance; + int from_tag; } rev_name; static long cutoff = LONG_MAX; @@ -24,16 +25,43 @@ static int is_better_name(struct rev_name *name, const char *tip_name, unsigned long taggerdate, int generation, - int distance) + int distance, + int from_tag) { - return (name->taggerdate > taggerdate || - (name->taggerdate == taggerdate && - name->distance > distance)); + /* + * When comparing names based on tags, prefer names + * based on the older tag, even if it is farther away. + */ + if (from_tag && name->from_tag) + return (name->taggerdate > taggerdate || + (name->taggerdate == taggerdate && + name->distance > distance)); + + /* + * We know that at least one of them is a non-tag at this point. + * favor a tag over a non-tag. + */ + if (name->from_tag != from_tag) + return from_tag; + + /* + * We are now looking at two non-tags. Tiebreak to favor + * shorter hops. + */ + if (name->distance != distance) + return name->distance > distance; + + /* ... or tiebreak to favor older date */ + if (name->taggerdate != taggerdate) + return name->taggerdate > taggerdate; + + /* keep the current one if we cannot decide */ + return 0; } static void name_rev(struct commit *commit, const char *tip_name, unsigned long taggerdate, - int generation, int distance, + int generation, int distance, int from_tag, int deref) { struct rev_name *name = (struct rev_name *)commit->util; @@ -57,12 +85,13 @@ static void name_rev(struct commit *commit, commit->util = name; goto copy_data; } else if (is_better_name(name, tip_name, taggerdate, - generation, distance)) { + generation, distance, from_tag)) { copy_data: name->tip_name = tip_name; name->taggerdate = taggerdate; name->generation = generation; name->distance = distance; + name->from_tag = from_tag; } else return; @@ -82,10 +111,12 @@ static void name_rev(struct commit *commit, parent_number); name_rev(parents->item, new_name, taggerdate, 0, - distance + MERGE_TRAVERSAL_WEIGHT, 0); + distance + MERGE_TRAVERSAL_WEIGHT, + from_tag, 0); } else { name_rev(parents->item, tip_name, taggerdate, - generation + 1, distance + 1, 0); + generation + 1, distance + 1, + from_tag, 0); } } } @@ -216,9 +247,13 @@ static int name_ref(const char *path, const struct object_id *oid, int flags, vo } if (o && o->type == OBJ_COMMIT) { struct commit *commit = (struct commit *)o; + int from_tag = starts_with(path, "refs/tags/"); + if (taggerdate == ULONG_MAX) + taggerdate = ((struct commit *)o)->date; path = name_ref_abbrev(path, can_abbreviate_output); - name_rev(commit, xstrdup(path), taggerdate, 0, 0, deref); + name_rev(commit, xstrdup(path), taggerdate, 0, 0, + from_tag, deref); } return 0; } diff --git a/t/t4202-log.sh b/t/t4202-log.sh index f577990716..4afd8135cd 100755 --- a/t/t4202-log.sh +++ b/t/t4202-log.sh @@ -399,7 +399,7 @@ cat > expect <<\EOF | | | | Merge branch 'side' | | -| * commit side +| * commit tags/side-2 | | Author: A U Thor | | | | side-2 -- 2.12.2.712.gba4c48c431