mq: new commands qselect, qguard

implement quilt-style guards for mq.

guards allow to control whether patch can be pushed.

if guard X is active and patch is guarded by +X (called "posative guard"),
patch can be pushed.  if patch is guarded by -X (called "nagative guard"),
patch cannot be pushed and is skipped.

use qguard to set/list guards on patches.  use qselect to set/list
active guards.

also "qseries -v" prints guarded patches with "G" now.

tests/test-mq-guards

@@ -0,0 +1,62
+#!/bin/sh
+
+HGRCPATH=$HGTMP/.hgrc; export HGRCPATH
+echo "[extensions]" >> $HGTMP/.hgrc
+echo "mq=" >> $HGTMP/.hgrc
+
+hg init
+hg qinit
+
+echo x > x
+hg ci -Ama
+
+hg qnew a.patch
+echo a > a
+hg add a
+hg qrefresh
+
+hg qnew b.patch
+echo b > b
+hg add b
+hg qrefresh
+
+hg qnew c.patch
+echo c > c
+hg add c
+hg qrefresh
+
+hg qpop -a
+
+echo % should fail
+hg qguard +fail
+
+hg qpush
+echo % should guard a.patch
+hg qguard +a
+echo % should print +a
+hg qguard
+hg qpop
+
+hg qguard a.patch
+echo % should push b.patch
+hg qpush
+
+hg qpop
+hg qselect a
+echo % should push a.patch
+hg qpush
+
+hg qguard c.patch -a
+echo % should print -a
+hg qguard c.patch
+
+echo % should skip c.patch
+hg qpush -a
+
+hg qguard -n c.patch
+echo % should push c.patch
+hg qpush -a
+
+hg qpop -a
+hg qselect -n
+hg qpush -a

hgext/mq.py

@@ -65,14 +65,17 class queue:
         self.series_dirty = 0
         self.series_path = "series"
         self.status_path = "status"
+        self.guards_path = "guards"
+        self.active_guards = None
+        self.guards_dirty = False
 
         if os.path.exists(self.join(self.series_path)):
             self.full_series = self.opener(self.series_path).read().splitlines()
         self.parse_series()
 
         if os.path.exists(self.join(self.status_path)):
-            self.applied = [statusentry(l)
-                            for l in self.opener(self.status_path).read().splitlines()]
+            lines = self.opener(self.status_path).read().splitlines()
+            self.applied = [statusentry(l) for l in lines]
 
     def join(self, *p):
         return os.path.join(self.path, *p)
@@ -90,12 +93,122 class queue:
             index += 1
         return None
 
+    guard_re = re.compile(r'\s?#([-+][^-+# \t\r\n\f][^# \t\r\n\f]*)')
+
     def parse_series(self):
         self.series = []
+        self.series_guards = []
         for l in self.full_series:
-            s = l.split('#', 1)[0].strip()
-            if s:
-                self.series.append(s)
+            h = l.find('#')
+            if h == -1:
+                patch = l
+                comment = ''
+            elif h == 0:
+                continue
+            else:
+                patch = l[:h]
+                comment = l[h:]
+            patch = patch.strip()
+            if patch:
+                self.series.append(patch)
+                self.series_guards.append(self.guard_re.findall(comment))
+
+    def check_guard(self, guard):
+        bad_chars = '# \t\r\n\f'
+        first = guard[0]
+        for c in '-+':
+            if first == c:
+                return (_('guard %r starts with invalid character: %r') %
+                        (guard, c))
+        for c in bad_chars:
+            if c in guard:
+                return _('invalid character in guard %r: %r') % (guard, c)
+        
+    def set_active(self, guards):
+        for guard in guards:
+            bad = self.check_guard(guard)
+            if bad:
+                raise util.Abort(bad)
+        guards = dict.fromkeys(guards).keys()
+        guards.sort()
+        self.ui.debug('active guards: %s\n' % ' '.join(guards))
+        self.active_guards = guards
+        self.guards_dirty = True
+
+    def active(self):
+        if self.active_guards is None:
+            self.active_guards = []
+            try:
+                guards = self.opener(self.guards_path).read().split()
+            except IOError, err:
+                if err.errno != errno.ENOENT: raise
+                guards = []
+            for i, guard in enumerate(guards):
+                bad = self.check_guard(guard)
+                if bad:
+                    self.ui.warn('%s:%d: %s\n' %
+                                 (self.join(self.guards_path), i + 1, bad))
+                else:
+                    self.active_guards.append(guard)
+        return self.active_guards
+
+    def set_guards(self, idx, guards):
+        for g in guards:
+            if len(g) < 2:
+                raise util.Abort(_('guard %r too short') % g)
+            if g[0] not in '-+':
+                raise util.Abort(_('guard %r starts with invalid char') % g)
+            bad = self.check_guard(g[1:])
+            if bad:
+                raise util.Abort(bad)
+        drop = self.guard_re.sub('', self.full_series[idx])
+        self.full_series[idx] = drop + ''.join([' #' + g for g in guards])
+        self.parse_series()
+        self.series_dirty = True
+        
+    def pushable(self, idx):
+        if isinstance(idx, str):
+            idx = self.series.index(idx)
+        patchguards = self.series_guards[idx]
+        if not patchguards:
+            return True, None
+        default = False
+        guards = self.active()
+        exactneg = [g for g in patchguards if g[0] == '-' and g[1:] in guards]
+        if exactneg:
+            return False, exactneg[0]
+        pos = [g for g in patchguards if g[0] == '+']
+        exactpos = [g for g in pos if g[1:] in guards]
+        if pos:
+            if exactpos:
+                return True, exactpos[0]
+            return False, ''
+        return True, ''
+
+    def explain_pushable(self, idx, all_patches=False):
+        write = all_patches and self.ui.write or self.ui.warn
+        if all_patches or self.ui.verbose:
+            if isinstance(idx, str):
+                idx = self.series.index(idx)
+            pushable, why = self.pushable(idx)
+            if all_patches and pushable:
+                if why is None:
+                    write(_('allowing %s - no guards in effect\n') %
+                          self.series[idx])
+                else:
+                    if not why:
+                        write(_('allowing %s - no matching negative guards\n') %
+                              self.series[idx])
+                    else:
+                        write(_('allowing %s - guarded by %r\n') %
+                              (self.series[idx], why))
+            if not pushable:
+                if why and why[0] in '-+':
+                    write(_('skipping %s - guarded by %r\n') %
+                          (self.series[idx], why))
+                else:
+                    write(_('skipping %s - no matching guards\n') %
+                          self.series[idx])
 
     def save_dirty(self):
         def write_list(items, path):
@@ -105,6 +218,7 class queue:
             fp.close()
         if self.applied_dirty: write_list(map(str, self.applied), self.status_path)
         if self.series_dirty: write_list(self.full_series, self.series_path)
+        if self.guards_dirty: write_list(self.active_guards, self.guards_path)
 
     def readheaders(self, patch):
         def eatdiff(lines):
@@ -257,7 +371,10 class queue:
             if not patch:
                 self.ui.warn("patch %s does not exist\n" % patch)
                 return (1, None)
-
+            pushable, reason = self.pushable(patch)
+            if not pushable:
+                self.explain_pushable(patch, all_patches=True)
+                continue
             info = mergeq.isapplied(patch)
             if not info:
                 self.ui.warn("patch %s is not applied\n" % patch)
@@ -321,6 +438,10 class queue:
         tr = repo.transaction()
         n = None
         for patch in series:
+            pushable, reason = self.pushable(patch)
+            if not pushable:
+                self.explain_pushable(patch, all_patches=True)
+                continue
             self.ui.warn("applying %s\n" % patch)
             pf = os.path.join(patchdir, patch)
 
@@ -639,8 +760,7 class queue:
                 pass
             else:
                 if sno < len(self.series):
-                    patch = self.series[sno]
-                    return patch
+                    return self.series[sno]
             if not strict:
                 # return any partial match made above
                 if res:
@@ -926,18 +1046,26 class queue:
             start = self.series_end()
         else:
             start = self.series.index(patch) + 1
-        return [(i, self.series[i]) for i in xrange(start, len(self.series))]
+        unapplied = []
+        for i in xrange(start, len(self.series)):
+            pushable, reason = self.pushable(i)
+            if pushable:
+                unapplied.append((i, self.series[i]))
+            self.explain_pushable(i)
+        return unapplied
 
     def qseries(self, repo, missing=None, summary=False):
-        start = self.series_end()
+        start = self.series_end(all_patches=True)
         if not missing:
             for i in range(len(self.series)):
                 patch = self.series[i]
                 if self.ui.verbose:
                     if i < start:
                         status = 'A'
+                    elif self.pushable(i)[0]:
+                        status = 'U'
                     else:
-                        status = 'U'
+                        status = 'G'
                     self.ui.write('%d %s ' % (i, status))
                 if summary:
                     msg = self.readheaders(patch)[0]
@@ -1060,16 +1188,27 class queue:
             return end + 1
         return 0
 
-    def series_end(self):
+    def series_end(self, all_patches=False):
         end = 0
+        def next(start):
+            if all_patches:
+                return start
+            i = start
+            while i < len(self.series):
+                p, reason = self.pushable(i)
+                if p:
+                    break
+                self.explain_pushable(i)
+                i += 1
+            return i
         if len(self.applied) > 0:
             p = self.applied[-1].name
             try:
                 end = self.series.index(p)
             except ValueError:
                 return 0
-            return end + 1
-        return end
+            return next(end + 1)
+        return next(end)
 
     def qapplied(self, repo, patch=None):
         if patch and patch not in self.series:
@@ -1372,6 +1511,51 def fold(ui, repo, *files, **opts):
 
     q.save_dirty()
 
+def guard(ui, repo, *args, **opts):
+    '''set or print guards for a patch
+
+    guards control whether a patch can be pushed.  a patch with no
+    guards is aways pushed.  a patch with posative guard ("+foo") is
+    pushed only if qselect command enables guard "foo".  a patch with
+    nagative guard ("-foo") is never pushed if qselect command enables
+    guard "foo".
+
+    with no arguments, default is to print current active guards.
+    with arguments, set active guards for patch.
+
+    to set nagative guard "-foo" on topmost patch ("--" is needed so
+    hg will not interpret "-foo" as argument):
+      hg qguard -- -foo
+
+    to set guards on other patch:
+      hg qguard other.patch +2.6.17 -stable    
+    '''
+    def status(idx):
+        guards = q.series_guards[idx] or ['unguarded']
+        ui.write('%s: %s\n' % (q.series[idx], ' '.join(guards)))
+    q = repo.mq
+    patch = None
+    args = list(args)
+    if opts['list']:
+        if args or opts['none']:
+            raise util.Abort(_('cannot mix -l/--list with options or arguments'))
+        for i in xrange(len(q.series)):
+            status(i)
+        return
+    if not args or args[0][0:1] in '-+':
+        if not q.applied:
+            raise util.Abort(_('no patches applied'))
+        patch = q.applied[-1].name
+    if patch is None and args[0][0:1] not in '-+':
+        patch = args.pop(0)
+    if patch is None:
+        raise util.Abort(_('no patch to work with'))
+    if args or opts['none']:
+        q.set_guards(q.find_series(patch), args)
+        q.save_dirty()
+    else:
+        status(q.series.index(q.lookup(patch)))
+
 def header(ui, repo, patch=None):
     """Print the header of the topmost or specified patch"""
     q = repo.mq
@@ -1546,6 +1730,69 def strip(ui, repo, rev, **opts):
     repo.mq.strip(repo, rev, backup=backup)
     return 0
 
+def select(ui, repo, *args, **opts):
+    '''set or print guarded patches to push
+
+    use qguard command to set or print guards on patch.  then use
+    qselect to tell mq which guards to use.  example:
+
+        qguard foo.patch -stable    (nagative guard)
+        qguard bar.patch +stable    (posative guard)
+        qselect stable
+
+    this sets "stable" guard.  mq will skip foo.patch (because it has
+    nagative match) but push bar.patch (because it has posative
+    match).
+
+    with no arguments, default is to print current active guards.
+    with arguments, set active guards as given.
+    
+    use -n/--none to deactivate guards (no other arguments needed).
+    when no guards active, patches with posative guards are skipped,
+    patches with nagative guards are pushed.
+
+    use -s/--series to print list of all guards in series file (no
+    other arguments needed).  use -v for more information.'''
+
+    q = repo.mq
+    guards = q.active()
+    if args or opts['none']:
+        q.set_active(args)
+        q.save_dirty()
+        if not args:
+            ui.status(_('guards deactivated\n'))
+        if q.series:
+            pushable = [p for p in q.unapplied(repo) if q.pushable(p[0])[0]]
+            ui.status(_('%d of %d unapplied patches active\n') %
+                      (len(pushable), len(q.series)))
+    elif opts['series']:
+        guards = {}
+        noguards = 0
+        for gs in q.series_guards:
+            if not gs:
+                noguards += 1
+            for g in gs:
+                guards.setdefault(g, 0)
+                guards[g] += 1
+        if ui.verbose:
+            guards['NONE'] = noguards
+        guards = guards.items()
+        guards.sort(lambda a, b: cmp(a[0][1:], b[0][1:]))
+        if guards:
+            ui.note(_('guards in series file:\n'))
+            for guard, count in guards:
+                ui.note('%2d  ' % count)
+                ui.write(guard, '\n')
+        else:
+            ui.note(_('no guards in series file\n'))
+    else:
+        if guards:
+            ui.note(_('active guards:\n'))
+            for g in guards:
+                ui.write(g, '\n')
+        else:
+            ui.write(_('no active guards\n'))
+
 def version(ui, q=None):
     """print the version number of the mq extension"""
     ui.write("mq version %s\n" % versionstr)
@@ -1605,6 +1852,9 cmdtable = {
           ('m', 'message', '', _('set patch header to <text>')),
           ('l', 'logfile', '', _('set patch header to contents of <file>'))],
          'hg qfold [-e] [-m <text>] [-l <file] PATCH...'),
+    'qguard': (guard, [('l', 'list', None, _('list all patches and guards')),
+                       ('n', 'none', None, _('drop all guards'))],
+               'hg qguard [PATCH] [+GUARD...] [-GUARD...]'),
     'qheader': (header, [],
                 _('hg qheader [PATCH]')),
     "^qimport":
@@ -1662,6 +1912,10 cmdtable = {
           ('e', 'empty', None, 'clear queue status file'),
           ('f', 'force', None, 'force copy')],
          'hg qsave [-m TEXT] [-l FILE] [-c] [-n NAME] [-e] [-f]'),
+    "qselect": (select,
+                [('n', 'none', None, _('disable all guards')),
+                 ('s', 'series', None, _('list all guards in series file'))],
+                'hg qselect [GUARDS]'),
     "qseries":
         (series,
          [('m', 'missing', None, 'print patches not in series'),

tests/test-mq.out

@@ -30,6 +30,7 list of commands (use "hg help -v mq" to
  qdelete      remove a patch from the series file
  qdiff        diff of the current patch
  qfold        fold the named patches into the current patch
+ qguard       set or print guards for a patch
  qheader      Print the header of the topmost or specified patch
  qimport      import a patch
  qinit        init a new queue repository
@@ -42,6 +43,7 list of commands (use "hg help -v mq" to
  qrename      rename a patch
  qrestore     restore the queue state saved by a rev
  qsave        save current queue state
+ qselect      set or print guarded patches to push
  qseries      print the entire series file
  qtop         print the name of the current patch
  qunapplied   print the patches not yet applied