cmdutil: replace sys.maxint with None as default value in loglimit

Semantically, it is better to use None over any other value when there is
"no value". Using maxint in this context is quite hackish, and is not forward
compatible.

hgext/graphlog.py

@@ -250,7 +250,8 b' def graphlog(ui, repo, path=None, **opts'
     if path: # could be reset in canonpath
         revdag = graphmod.filerevs(repo, path, start, stop, limit)
     else:
-        stop = max(stop, start - limit + 1)
+        if limit is not None:
+            stop = max(stop, start - limit + 1)
         revdag = graphmod.revisions(repo, start, stop)
 
     displayer = show_changeset(ui, repo, opts, buffered=True)
@@ -260,7 +261,7 b' def graphlog(ui, repo, path=None, **opts'
 def graphrevs(repo, nodes, opts):
     limit = cmdutil.loglimit(opts)
     nodes.reverse()
-    if limit < sys.maxint:
+    if limit is not None:
         nodes = nodes[:limit]
     return graphmod.nodes(repo, nodes)
 

mercurial/cmdutil.py

@@ -95,7 +95,7 b' def loglimit(opts):'
             raise util.Abort(_('limit must be a positive integer'))
         if limit <= 0: raise util.Abort(_('limit must be positive'))
     else:
-        limit = sys.maxint
+        limit = None
     return limit
 
 def remoteui(src, opts):

mercurial/commands.py

@@ -1924,7 +1924,7 b' def incoming(ui, repo, source="default",'
         displayer = cmdutil.show_changeset(ui, other, opts)
         count = 0
         for n in o:
-            if count >= limit:
+            if limit is not None and count >= limit:
                 break
             parents = [p for p in other.changelog.parents(n) if p != nullid]
             if opts.get('no_merges') and len(parents) == 2:
@@ -2179,7 +2179,7 b' def outgoing(ui, repo, dest=None, **opts'
     displayer = cmdutil.show_changeset(ui, repo, opts)
     count = 0
     for n in o:
-        if count >= limit:
+        if limit is not None and count >= limit:
             break
         parents = [p for p in repo.changelog.parents(n) if p != nullid]
         if opts.get('no_merges') and len(parents) == 2:

mercurial/graphmod.py

@@ -17,7 +17,6 b' context of the graph returned. Type is a'
 Data depends on type.
 """
 
-import sys
 from mercurial.node import nullrev
 
 CHANGESET = 'C'
@@ -37,7 +36,7 b' def revisions(repo, start, stop):'
         yield (cur, CHANGESET, ctx, sorted(parents))
         cur -= 1
 
-def filerevs(repo, path, start, stop, limit=sys.maxint):
+def filerevs(repo, path, start, stop, limit=None):
     """file cset DAG generator yielding (id, CHANGESET, ctx, [parentids]) tuples
 
     This generator function walks through the revision history of a single