import: avoid editor invocation when importing with "--exact" for exact-ness

Before this patch, external editor is invoked when imported patch has
no commit message, even if "--exact" is specified. Then, exact-ness is
broken, because empty commit message causes failure of committing.

This patch avoids editor invocation at importing with "--exact" for
exact-ness, because commit message in the patch should be kept as it
is in such case, even if it is empty.

mercurial/cmdutil.py

@@ -688,6 +688,9 b' def tryimportone(ui, repo, hunk, parents'
                 else:
                     m = scmutil.matchfiles(repo, files or [])
                 editform = mergeeditform(repo[None], 'import.normal')
+                if opts.get('exact'):
+                    editor = None
+                else:
                 editor = getcommiteditor(editform=editform, **opts)
                 n = repo.commit(message, opts.get('user') or user,
                                 opts.get('date') or date, match=m,
@@ -705,6 +708,9 b' def tryimportone(ui, repo, hunk, parents'
                                     files, eolmode=None)
                 except patch.PatchError, e:
                     raise util.Abort(str(e))
+                if opts.get('exact'):
+                    editor = None
+                else:
                 editor = getcommiteditor(editform='import.bypass')
                 memctx = context.makememctx(repo, (p1.node(), p2.node()),
                                             message,

tests/test-import-bypass.t

@@ -226,6 +226,25 b' Test applying multiple patches with --ex'
 
   $ cd ..
 
+Test avoiding editor invocation at applying the patch with --exact
+even if commit message is empty
+
+  $ cd repo-options
+
+  $ echo a >> a
+  $ hg commit -m ' '
+  $ hg tip -T "{node}\n"
+  1b77bc7d1db9f0e7f1716d515b630516ab386c89
+  $ hg export -o ../empty-log.diff .
+  $ hg update -q -C ".^1"
+  $ hg --config extensions.strip= strip -q tip
+  $ HGEDITOR=cat hg import --exact --bypass ../empty-log.diff
+  applying ../empty-log.diff
+  $ hg tip -T "{node}\n"
+  1b77bc7d1db9f0e7f1716d515b630516ab386c89
+
+  $ cd ..
+
 #if symlink execbit
 
 Test complicated patch with --exact

tests/test-import.t

@@ -107,6 +107,22 b" the commit message, regardless of '--edi"
   HG: changed a
   abort: empty commit message
   [255]
+
+Test avoiding editor invocation at applying the patch with --exact,
+even if commit message is empty
+
+  $ echo a >> b/a
+  $ hg --cwd b commit -m ' '
+  $ hg --cwd b tip -T "{node}\n"
+  d8804f3f5396d800812f579c8452796a5993bdb2
+  $ hg --cwd b export -o ../empty-log.diff .
+  $ hg --cwd b update -q -C ".^1"
+  $ hg --cwd b --config extensions.strip= strip -q tip
+  $ HGEDITOR=cat hg --cwd b import --exact ../empty-log.diff
+  applying ../empty-log.diff
+  $ hg --cwd b tip -T "{node}\n"
+  d8804f3f5396d800812f579c8452796a5993bdb2
+
   $ rm -r b