graphlog: always sort revisions topologically

The grapher cannot really handled revisions if they are not emitted in
topological order. The previous 'reverse()' revset was not enough to achieve
that and was replaced by an explicit sort call for simplicity. The --limit
option is now also handled as usual with cmdutil.loglimit() instead of a
'limit' revset.

hgext/graphlog.py

@@ -288,10 +288,6 b' def revset(pats, opts):'
         revset = ' and '.join(revset)
     else:
         revset = 'all()'
-    # we want reverted revset to build graph
-    revset = 'reverse(%s)' % revset
-    if opts['limit']:
-        revset = 'limit(%s, %s)' % (revset, opts['limit'])
     return revset
 
 def generate(ui, dag, displayer, showparents, edgefn):
@@ -318,7 +314,10 b' def graphlog(ui, repo, *pats, **opts):'
 
     check_unsupported_flags(pats, opts)
 
-    revs = revrange(repo, [revset(pats, opts)])
+    revs = sorted(revrange(repo, [revset(pats, opts)]), reverse=1)
+    limit = cmdutil.loglimit(opts)
+    if limit is not None:
+        revs = revs[:limit]
     revdag = graphmod.dagwalker(repo, revs)
 
     displayer = show_changeset(ui, repo, opts, buffered=True)

tests/test-glog.t

@@ -1319,13 +1319,12 b' File + limit + -ra:b, b < tip:'
 file(File) + limit + -ra:b, b < tip:
 
   $ hg glog -l1 -r32:34 -r 'file("a")'
-  o    changeset:   31:621d83e11f67
-  |\   parent:      21:d42a756af44d
-  | |  parent:      30:6e11cd4b648f
-  | |  user:        test
-  | |  date:        Thu Jan 01 00:00:31 1970 +0000
-  | |  summary:     (31) expand
-  | |
+  o  changeset:   34:fea3ac5810e0
+  |  parent:      32:d06dffa21a31
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:34 1970 +0000
+  |  summary:     (34) head
+  |
 
 limit(file(File) and a::b), b < tip:
 
@@ -1457,8 +1456,16 b' Test log -G options'
 
 Test multiple revision specifications are correctly handled
 
-  $ hg log -G -r 27 -r 25 --branch default --template '{rev}\n'
-  o    25
+  $ hg log -G -r 27 -r 25 -r 21 -r 34 -r 32 -r 31 --template '{rev}\n'
+  o  34
+  |
+  o    32
   |\
-  +---o  27
-  | |
+  | o    31
+  | |\
+  o | |  27
+  |/ /
+  | o  25
+  |/
+  o    21
+  |\