[StGit PATCH 06/13] Refactor Series.push_patch

["David Kågedal" <davidk@lysator.liu.se>]

Refactor the Series.push_patch function to make the code flow
simpler. It identifies the simple case and handles it early, and
reduces the number of if statements.

Most changes are simply indentation changes.

Signed-off-by: David Kågedal <davidk@lysator.liu.se>
---

 stgit/stack.py |   87 ++++++++++++++++++++++++++++++--------------------------
 1 files changed, 46 insertions(+), 41 deletions(-)


diff --git a/stgit/stack.py b/stgit/stack.py
index f31f308..9b8ed6e 100644
--- a/stgit/stack.py
+++ b/stgit/stack.py
@@ -1054,60 +1054,65 @@ class Series(PatchSet):
         head = git.get_head()
         bottom = patch.get_bottom()
         top = patch.get_top()
-
-        ex = None
-        modified = False
-
         # top != bottom always since we have a commit for each patch
+
         if head == bottom:
-            # reset the backup information. No need for logging
+            # A fast-forward push. Just reset the backup
+            # information. No need for logging
             patch.set_bottom(bottom, backup = True)
             patch.set_top(top, backup = True)
 
             git.switch(top)
-        else:
-            # new patch needs to be refreshed.
-            # The current patch is empty after merge.
-            patch.set_bottom(head, backup = True)
-            patch.set_top(head, backup = True)
-
-            # Try the fast applying first. If this fails, fall back to the
-            # three-way merge
-            if not git.apply_diff(bottom, top):
-                # if git.apply_diff() fails, the patch requires a diff3
-                # merge and can be reported as modified
-                modified = True
-
-                # merge can fail but the patch needs to be pushed
-                try:
-                    git.merge(bottom, head, top, recursive = True)
-                except git.GitException, ex:
-                    out.error('The merge failed during "push".',
-                              'Use "refresh" after fixing the conflicts or'
-                              ' revert the operation with "push --undo".')
+            append_string(self.__applied_file, name)
+
+            unapplied.remove(name)
+            write_strings(self.__unapplied_file, unapplied)
+            return False
+
+        # Need to create a new commit an merge in the old patch
+        ex = None
+        modified = False
+
+        # new patch needs to be refreshed.
+        # The current patch is empty after merge.
+        patch.set_bottom(head, backup = True)
+        patch.set_top(head, backup = True)
+
+        # Try the fast applying first. If this fails, fall back to the
+        # three-way merge
+        if not git.apply_diff(bottom, top):
+            # if git.apply_diff() fails, the patch requires a diff3
+            # merge and can be reported as modified
+            modified = True
+
+            # merge can fail but the patch needs to be pushed
+            try:
+                git.merge(bottom, head, top, recursive = True)
+            except git.GitException, ex:
+                out.error('The merge failed during "push".',
+                          'Use "refresh" after fixing the conflicts or'
+                          ' revert the operation with "push --undo".')
 
         append_string(self.__applied_file, name)
 
         unapplied.remove(name)
         write_strings(self.__unapplied_file, unapplied)
 
-        # head == bottom case doesn't need to refresh the patch
-        if head != bottom:
-            if not ex:
-                # if the merge was OK and no conflicts, just refresh the patch
-                # The GIT cache was already updated by the merge operation
-                if modified:
-                    log = 'push(m)'
-                else:
-                    log = 'push'
-                self.refresh_patch(cache_update = False, log = log)
+        if not ex:
+            # if the merge was OK and no conflicts, just refresh the patch
+            # The GIT cache was already updated by the merge operation
+            if modified:
+                log = 'push(m)'
             else:
-                # we store the correctly merged files only for
-                # tracking the conflict history. Note that the
-                # git.merge() operations should always leave the index
-                # in a valid state (i.e. only stage 0 files)
-                self.refresh_patch(cache_update = False, log = 'push(c)')
-                raise StackException, str(ex)
+                log = 'push'
+            self.refresh_patch(cache_update = False, log = log)
+        else:
+            # we store the correctly merged files only for
+            # tracking the conflict history. Note that the
+            # git.merge() operations should always leave the index
+            # in a valid state (i.e. only stage 0 files)
+            self.refresh_patch(cache_update = False, log = 'push(c)')
+            raise StackException, str(ex)
 
         return modified