summary: introduce "summaryremotehooks" to avoid redundant incoming/outgoing check

This patch introduces "summaryremotehooks" to avoid redundant
incoming/outgoing check for "hg summary" in other than
"commands.summary".

Only if "--remote" is not specified for "hg summary", hooks registered
in "summaryremotehooks" are invoked with "None" as "changes" argument
at first, and they should return tuple of two booleans meaning
"whether incomings are needed" and "whether outgoings are needed".

If no hooks return tuple containing "True", "hg summary" does nothing
any more, because incoming/outgoing check is not needed.

Otherwise, hooks are invoked again: at this time, "changes" argument
refers the result of incoming/outgoing check.

This patch also prevents RepoError from being raised if "--remote" is
not specified for "hg summary", because of backward compatibility for
"hg summary --large" without "--remote".

mercurial/cmdutil.py

@@ -2382,6 +2382,16 b' def command(table):'
 # a list of (ui, repo) functions called by commands.summary
 summaryhooks = util.hooks()
 
+# a list of (ui, repo, opts, changes) functions called by commands.summary.
+#
+# functions should return tuple of booleans below, if 'changes' is None:
+#  (whether-incomings-are-needed, whether-outgoings-are-needed)
+#
+# otherwise, 'changes' is a tuple of tuples below:
+#  - (sourceurl, sourcebranch, sourcepeer, incoming)
+#  - (desturl,   destbranch,   destpeer,   outgoing)
+summaryremotehooks = util.hooks()
+
 # A list of state files kept by multistep operations like graft.
 # Since graft cannot be aborted, it is considered 'clearable' by update.
 # note: bisect is intentionally excluded

mercurial/commands.py

@@ -5525,11 +5525,23 b' def summary(ui, repo, **opts):'
         needsincoming, needsoutgoing = True, True
     else:
         needsincoming, needsoutgoing = False, False
+        for i, o in cmdutil.summaryremotehooks(ui, repo, opts, None):
+            if i:
+                needsincoming = True
+            if o:
+                needsoutgoing = True
+        if not needsincoming and not needsoutgoing:
+            return
 
     def getincoming():
         source, branches = hg.parseurl(ui.expandpath('default'))
         sbranch = branches[0]
-        other = hg.peer(repo, {}, source)
+        try:
+            other = hg.peer(repo, {}, source)
+        except error.RepoError:
+            if opts.get('remote'):
+                raise
+            return source, sbranch, None, None, None
         revs, checkout = hg.addbranchrevs(repo, other, branches, None)
         if revs:
             revs = [other.lookup(rev) for rev in revs]
@@ -5549,8 +5561,16 b' def summary(ui, repo, **opts):'
         dbranch = branches[0]
         revs, checkout = hg.addbranchrevs(repo, repo, branches, None)
         if source != dest:
-            dother = hg.peer(repo, {}, dest)
+            try:
+                dother = hg.peer(repo, {}, dest)
+            except error.RepoError:
+                if opts.get('remote'):
+                    raise
+                return dest, dbranch, None, None
             ui.debug('comparing with %s\n' % util.hidepassword(dest))
+        elif sother is None:
+            # there is no explicit destination peer, but source one is invalid
+            return dest, dbranch, None, None
         else:
             dother = sother
         if (source != dest or (sbranch is not None and sbranch != dbranch)):
@@ -5595,6 +5615,10 b' def summary(ui, repo, **opts):'
             # i18n: column positioning for "hg summary"
             ui.status(_('remote: (synced)\n'))
 
+    cmdutil.summaryremotehooks(ui, repo, opts,
+                               ((source, sbranch, sother, commoninc),
+                                (dest, dbranch, dother, outgoing)))
+
 @command('tag',
     [('f', 'force', None, _('force tag')),
     ('l', 'local', None, _('make the tag local')),