git-p4: Fix import of changesets with file deletions

Commit 3a70cdf made readP4Files abort quickly
when the changeset only contains files that are marked for deletion with an empty return
value, which caused the commit to not do anything.

This commit changes readP4Files to distinguish between files that need to be passed to p4
print and files that have no content ("deleted") and merge them in the returned
list.

Signed-off-by: Simon Hausmann <simon@lst.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/fast-import/git-p4

@@ -850,29 +850,32 @@ class P4Sync(Command):
 
     ## Should move this out, doesn't use SELF.
     def readP4Files(self, files):
+        filesForCommit = []
+        filesToRead = []
+
         for f in files:
+            includeFile = True
             for val in self.clientSpecDirs:
                 if f['path'].startswith(val[0]):
-                    if val[1] > 0:
-                        f['include'] = True
-                    else:
-                        f['include'] = False
+                    if val[1] <= 0:
+                        includeFile = False
                     break
 
-        files = [f for f in files
-                 if f['action'] != 'delete' and
-                 (f.has_key('include') == False or f['include'] == True)]
+            if includeFile:
+                filesForCommit.append(f)
+                if f['action'] != 'delete':
+                    filesToRead.append(f)
 
-        if not files:
-            return []
+        filedata = []
+        if len(filesToRead) > 0:
+            filedata = p4CmdList('-x - print',
+                                 stdin='\n'.join(['%s#%s' % (f['path'], f['rev'])
+                                                  for f in filesToRead]),
+                                 stdin_mode='w+')
 
-        filedata = p4CmdList('-x - print',
-                             stdin='\n'.join(['%s#%s' % (f['path'], f['rev'])
-                                              for f in files]),
-                             stdin_mode='w+')
-        if "p4ExitCode" in filedata[0]:
-            die("Problems executing p4. Error: [%d]."
-                % (filedata[0]['p4ExitCode']));
+            if "p4ExitCode" in filedata[0]:
+                die("Problems executing p4. Error: [%d]."
+                    % (filedata[0]['p4ExitCode']));
 
         j = 0;
         contents = {}
@@ -896,10 +899,12 @@ class P4Sync(Command):
 
             contents[stat['depotFile']] = text
 
-        for f in files:
-            assert not f.has_key('data')
-            f['data'] = contents[f['path']]
-        return files
+        for f in filesForCommit:
+            path = f['path']
+            if contents.has_key(path):
+                f['data'] = contents[path]
+
+        return filesForCommit
 
     def commit(self, details, files, branch, branchPrefixes, parent = ""):
         epoch = details["time"]