[PATCH 3 of 4 V2] ui: use the new configoverride context manager instead of saving/restoring

[Laurent Charignon]

# HG changeset patch
# User Laurent Charignon <lcharignon at fb.com>
# Date 1431562081 25200
#      Wed May 13 17:08:01 2015 -0700
# Node ID cb2f0824776ea5d964813ab4bc5213e03b4e45fc
# Parent  480dbca00f19fb90b59f9c6fd511e4806fb642c4
ui: use the new configoverride context manager instead of saving/restoring

This patch changes all the point in the code (except two) where we used the
saving restoring logic for config to use the new configoverride contextmanager.
This makes the code more legible.

diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -386,16 +386,12 @@
     """
     phasemin = src.phase()
     def commitfunc(**kwargs):
-        phasebackup = repo.ui.backupconfig('phases', 'new-commit')
-        try:
-            repo.ui.setconfig('phases', 'new-commit', phasemin,
-                              'histedit')
+        with repo.ui.configoverride('phases', 'new-commit', phasemin,
+                                    'histedit'):
             extra = kwargs.get('extra', {}).copy()
             extra['histedit_source'] = src.hex()
             kwargs['extra'] = extra
             return repo.commit(**kwargs)
-        finally:
-            repo.ui.restoreconfig(phasebackup)
     return commitfunc
 
 def applychanges(ui, repo, ctx, opts):
@@ -574,14 +570,11 @@
         #       here. This is sufficient to solve issue3681 anyway.
         extra['histedit_source'] = '%s,%s' % (ctx.hex(), oldctx.hex())
         commitopts['extra'] = extra
-        phasebackup = repo.ui.backupconfig('phases', 'new-commit')
-        try:
-            phasemin = max(ctx.phase(), oldctx.phase())
-            repo.ui.setconfig('phases', 'new-commit', phasemin, 'histedit')
+        phasemin = max(ctx.phase(), oldctx.phase())
+        with repo.ui.configoverride('phases', 'new-commit', phasemin,
+                                    'histedit'):
             n = collapse(repo, ctx, repo[newnode], commitopts,
                          skipprompt=self.skipprompt())
-        finally:
-            repo.ui.restoreconfig(phasebackup)
         if n is None:
             return ctx, []
         hg.update(repo, n)
diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -540,15 +540,12 @@
         if extrafn:
             extrafn(ctx, extra)
 
-        backup = repo.ui.backupconfig('phases', 'new-commit')
-        try:
-            targetphase = max(ctx.phase(), phases.draft)
-            repo.ui.setconfig('phases', 'new-commit', targetphase, 'rebase')
+        targetphase = max(ctx.phase(), phases.draft)
+        with repo.ui.configoverride('phases', 'new-commit', targetphase,
+                                    'rebase'):
             # Commit might fail if unresolved files exist
             newnode = repo.commit(text=commitmsg, user=ctx.user(),
                                   date=ctx.date(), extra=extra, editor=editor)
-        finally:
-            repo.ui.restoreconfig(backup)
 
         repo.dirstate.setbranch(repo[newnode].branch())
         dsguard.close()
diff --git a/hgext/shelve.py b/hgext/shelve.py
--- a/hgext/shelve.py
+++ b/hgext/shelve.py
@@ -177,16 +177,15 @@
         hasmq = util.safehasattr(repo, 'mq')
         if hasmq:
             saved, repo.mq.checkapplied = repo.mq.checkapplied, False
-        backup = repo.ui.backupconfig('phases', 'new-commit')
-        try:
-            repo.ui. setconfig('phases', 'new-commit', phases.secret)
-            editor = cmdutil.getcommiteditor(editform='shelve.shelve', **opts)
-            return repo.commit(message, user, opts.get('date'), match,
-                               editor=editor)
-        finally:
-            repo.ui.restoreconfig(backup)
-            if hasmq:
-                repo.mq.checkapplied = saved
+        with repo.ui.configoverride('phases', 'new-commit', phases.secret):
+            try:
+                editor = cmdutil.getcommiteditor(editform='shelve.shelve',
+                        **opts)
+                return repo.commit(message, user, opts.get('date'), match,
+                                   editor=editor)
+            finally:
+                if hasmq:
+                    repo.mq.checkapplied = saved
 
     if parent.node() != nullid:
         desc = "changes to '%s'" % parent.description().split('\n', 1)[0]
@@ -568,15 +567,14 @@
                 if hasmq:
                     saved, repo.mq.checkapplied = repo.mq.checkapplied, False
 
-                backup = repo.ui.backupconfig('phases', 'new-commit')
-                try:
-                    repo.ui. setconfig('phases', 'new-commit', phases.secret)
-                    return repo.commit(message, 'shelve at localhost',
+                with repo.ui.configoverride('phases', 'new-commit',
+                                            phases.secret):
+                    try:
+                        return repo.commit(message, 'shelve at localhost',
                                        opts.get('date'), match)
-                finally:
-                    repo.ui.restoreconfig(backup)
-                    if hasmq:
-                        repo.mq.checkapplied = saved
+                    finally:
+                        if hasmq:
+                            repo.mq.checkapplied = saved
 
             tempopts = {}
             tempopts['message'] = "pending changes temporary commit"
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1893,12 +1893,8 @@
                     if not streamreqs - self.supportedformats:
                         self.stream_in(remote, streamreqs)
 
-        quiet = self.ui.backupconfig('ui', 'quietbookmarkmove')
-        try:
-            self.ui.setconfig('ui', 'quietbookmarkmove', True, 'clone')
+        with self.ui.configoverride('ui', 'quietbookmarkmove', True, 'clone'):
             ret = exchange.pull(self, remote, heads).cgresult
-        finally:
-            self.ui.restoreconfig(quiet)
         return ret
 
     def pushkey(self, namespace, key, old, new):