hg import: write the dirstate after every commit

This allows the transaction system to backup the correct file, so
that a future rollback can do the right thing.

This should fix issue963.

mercurial/commands.py

@@ -1632,6 +1632,9 b' def import_(ui, repo, patch1, *patches, '
                         repo.rollback()
                         raise util.Abort(_('patch is damaged' +
                                            ' or loses information'))
+                # Force a dirstate write so that the next transaction backups
+                # an up-do-date file.
+                repo.dirstate.write()
             finally:
                 os.unlink(tmpname)
     finally:

tests/test-import

@@ -111,6 +111,18 b' python mkmsg2.py | hg --cwd b import -'
 hg --cwd b tip --template '{desc}\n'
 rm -r b
 
+# We weren't backing up the correct dirstate file when importing many patches
+# (issue963)
+echo '% import patch1 patch2; rollback'
+echo line 3 >> a/a
+hg --cwd a ci -m'third change'
+hg --cwd a export -o '../patch%R' 1 2
+hg clone -qr0 a b
+hg --cwd b parents --template 'parent: #rev#\n'
+hg --cwd b import ../patch1 ../patch2
+hg --cwd b rollback
+hg --cwd b parents --template 'parent: #rev#\n'
+rm -r b
 
 # bug non regression test
 # importing a patch in a subdirectory failed at the commit stage

tests/test-import.out

@@ -112,6 +112,12 b' email patch'
 
 next line
 ---
+% import patch1 patch2; rollback
+parent: 0
+applying ../patch1
+applying ../patch2
+rolling back last transaction
+parent: 1
 % hg import in a subdirectory
 requesting all changes
 adding changesets