[PATCH] templates: add {lasttag} and {lasttagdistance} keywords

[Gilles Moris]

 mercurial/cmdutil.py |  40 ++++++++++++++++++++++++++++++++++++++++
 mercurial/help.py    |   3 +++
 tests/test-log       |  44 ++++++++++++++++++++++++++++++++++++++++++++
 tests/test-log.out   |  50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 137 insertions(+), 0 deletions(-)


# HG changeset patch
# User Gilles Moris <gilles.moris at free.fr>
# Date 1247087563 -7200
# Node ID bea99b6921ea2a76921b765cfa5fe4a9f5ffe6e1
# Parent  e1dacc2c0aaee8bfa4a1749ed504b3afed119adb
templates: add {lasttag} and {lasttagdistance} keywords.

Useful to build nightly version names and see on which tag a rev is based on.

Among tag ancestors, the one with the latest date, or with the longuest path if
there are multiple pathes to the same tag, is chosen.
This way, lasttag does not depend on the push/pull order and matches the
user's expectation, in particular in the case of a backout merge.
Only global tags are considered. The local tags (including 'tip' and automatic
MQ tags) are discarded.

Both lasttag and lasttagdistance are defined as String, so that they default to
an empty string if no tag is found.

diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -741,6 +741,35 @@
                                          'manifest': '{rev}:{node|formatnode}',
                                          'filecopy': '{name} ({source})'})
 
+    @util.propertycache
+    def lasttagmap(self):
+        '''get an array[rev] of latest tag tuple, each tuple being
+        (date of the latest tag, the [first] tag, distance to that tag).
+        Exclude "tip" and MQ tags from the search.
+        '''
+        defvalue = 0, '', -1
+        ltmap = [defvalue] * len(self.repo)
+
+        for r in range(len(self.repo)):
+            ctx = self.repo[r]
+
+            tags = [t for t in ctx.tags() if self.repo.tagtype(t) == 'global']
+            if tags:
+                ltmap[r] = ctx.date(), tags[0], 0
+            else:
+                # trick: use tuple comparison to sort by latest date first
+                # and if the dates (and by construction also the tag) are
+                # equal, by longuest path.
+                lasttag = reduce(max,
+                                 [ltmap[p.rev()] for p in ctx.parents()],
+                                 defvalue)
+                ldate, ltag, ldist = lasttag
+                # if no previous tag, nothing to do (leave default value)
+                if ltag:
+                    ltmap[r] = ldate, ltag, ldist + 1
+
+        return ltmap
+
     def use_template(self, t):
         '''set template string to use'''
         self.t.cache['changeset'] = t
@@ -874,6 +903,15 @@
                 removes += i[2]
             return '%s: +%s/-%s' % (files, adds, removes)
 
+        def showlasttag(**args):
+            return self.lasttagmap[ctx.rev()][1]
+        def showlasttagdistance(**args):
+            dist = self.lasttagmap[ctx.rev()][2]
+            if dist >= 0:
+                return str(dist)
+            else:
+                return ""
+
         defprops = {
             'author': ctx.user(),
             'branches': showbranches,
@@ -891,6 +929,8 @@
             'tags': showtags,
             'extras': showextras,
             'diffstat': showdiffstat,
+            'lasttag': showlasttag,
+            'lasttagdistance': showlasttagdistance,
             }
         props = props.copy()
         props.update(defprops)
diff --git a/mercurial/help.py b/mercurial/help.py
--- a/mercurial/help.py
+++ b/mercurial/help.py
@@ -369,6 +369,9 @@
     - file_adds: List of strings. Files added by this changeset.
     - file_mods: List of strings. Files modified by this changeset.
     - file_dels: List of strings. Files removed by this changeset.
+    - lasttag: String. Most recent global tag in the ancestors of this
+          changeset.
+    - lasttagdistance: String. Longuest path to the last tag.
     - node: String. The changeset identification hash, as a 40-character
           hexadecimal string.
     - parents: List of strings. The parents of the changeset.
diff --git a/tests/test-log b/tests/test-log
--- a/tests/test-log
+++ b/tests/test-log
@@ -118,4 +118,48 @@
 hg log -u "user1" -u "user2"
 hg log -u "user3"
 
+cd ..
+
+echo % lasttag
+hg init lasttag
+cd lasttag
+
+echo a > file
+hg ci -Am a -d '0 0'
+
+echo b >> file
+hg ci -m b -d '1 0'
+
+echo c >> head1
+hg ci -Am h1c -d '2 0'
+
+hg update -q 1
+echo d >> head2
+hg ci -Am h2d -d '3 0'
+
+echo e >> head2
+hg ci -m h2e -d '4 0'
+
+hg merge -q
+hg ci -m merge -d '5 0'
+
+echo % No tag set
+hg log --template '{rev}: {lasttag} {lasttagdistance}\n'
+
+echo % one common tag: longuest path wins
+hg tag -r 1 -m t1 -d '6 0' t1
+hg log --template '{rev}: {lasttag} {lasttagdistance}\n'
+
+echo % one ancestor tag: more recent wins
+hg tag -r 2 -m t2 -d '7 0' t2
+hg log --template '{rev}: {lasttag} {lasttagdistance}\n'
+
+echo % two branch tags: more recent wins
+hg tag -r 3 -m t3 -d '8 0' t3
+hg log --template '{rev}: {lasttag} {lasttagdistance}\n'
+
+echo % merged tag overrides
+hg tag -r 5 -m t5 -d '9 0' t5
+hg log --template '{rev}: {lasttag} {lasttagdistance}\n'
+
 exit 0
diff --git a/tests/test-log.out b/tests/test-log.out
--- a/tests/test-log.out
+++ b/tests/test-log.out
@@ -257,3 +257,53 @@
 date:        Thu Jan 01 00:00:00 1970 +0000
 summary:     a
 
+% lasttag
+adding file
+adding head1
+adding head2
+created new head
+% No tag set
+5:  
+4:  
+3:  
+2:  
+1:  
+0:  
+% one common tag: longuest path wins
+6: t1 4
+5: t1 3
+4: t1 2
+3: t1 1
+2: t1 1
+1: t1 0
+0:  
+% one ancestor tag: more recent wins
+7: t2 3
+6: t2 2
+5: t2 1
+4: t1 2
+3: t1 1
+2: t2 0
+1: t1 0
+0:  
+% two branch tags: more recent wins
+8: t3 5
+7: t3 4
+6: t3 3
+5: t3 2
+4: t3 1
+3: t3 0
+2: t2 0
+1: t1 0
+0:  
+% merged tag overrides
+9: t5 4
+8: t5 3
+7: t5 2
+6: t5 1
+5: t5 0
+4: t3 1
+3: t3 0
+2: t2 0
+1: t1 0
+0: