[StGit PATCH 6/6] Use the output from merge-recursive to list conflicts

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

From: David KÃ¥gedal <davidk@lysator.liu.se>

merge-recursive already has useful information about what the conflicts
were, so we reuse that when pushing.

Signed-off-by: David KÃ¥gedal <davidk@lysator.liu.se>
---
 stgit/git.py   |   27 +++++++++++++++++++++------
 stgit/stack.py |    2 ++
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/stgit/git.py b/stgit/git.py
index 63798bd..59423ab 100644
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -30,7 +30,14 @@ from sets import Set
 class GitException(Exception):
     pass
 
-
+class GitConflictException(GitException):
+    def __init__(self, conflicts):
+        GitException.__init__(self)
+        self.conflicts = conflicts
+    def __str__(self):
+        return "%d conflicts" % len(self.conflicts)
+    def list(self):
+        out.info(*self.conflicts)
 
 #
 # Classes
@@ -675,11 +682,19 @@ def merge_recursive(base, head1, head2):
     """
     refresh_index()
 
-    # use _output() to mask the verbose prints of the tool
-    try:
-        _output(['git-merge-recursive', base, '--', head1, head2])
-    except GitException:
-        raise GitException, 'GIT index merging failed (possible conflicts)'
+    # Duplicate _output(), since we need the exit status
+    p=popen2.Popen3(['git-merge-recursive', base, '--', head1, head2], True)
+    output = p.fromchild.readlines()
+    st = p.wait() >> 8
+    if st == 0:
+        # No problems
+        return
+    elif st == 1:
+        # There were conflicts
+        conflicts = [l.strip() for l in output if l.startswith('CONFLICT')]
+        raise GitConflictException(conflicts)
+    else:
+        raise GitException, 'git-merge-recursive failed (%s)' % (p.childerr.read().strip())
 
 def merge(base, head1, head2):
     """Perform a 3-way merge between base, head1 and head2 into the
diff --git a/stgit/stack.py b/stgit/stack.py
index 0e43f75..3b06ca5 100644
--- a/stgit/stack.py
+++ b/stgit/stack.py
@@ -1070,6 +1070,8 @@ class Series(PatchSet):
                 # merge can fail but the patch needs to be pushed
                 try:
                     git.merge_recursive(bottom, head, top)
+                except git.GitConflictException, ex:
+                    ex.list()
                 except git.GitException, ex:
                     out.error('The merge failed during "push".',
                               'Use "refresh" after fixing the conflicts or'
-- 
1.5.3.rc3.119.g1812