avoid removing old associated file when there is a merge conflict

It makes sense to keep the key used by the old version of an
associated file, until the merge conflict is resolved.

Note that, since in this case git diff is being run with --index, it's
not possible to use -1 or -3, which would let the keys
associated with the new versions of the file also be added. That would
be better, because it's possible that the local modification to the file
that caused the merge conflict has not yet gotten its new key recorded
in the db.

Opened a bug about a case this is thus not able to address.

Sponsored-by: Boyd Stephen Smith Jr. on Patreon

Database/Keys.hs

@@ -309,14 +309,18 @@ reconcileStaged qh = do
 	
 	procdiff (info:file:rest) changed
 		| ":" `S.isPrefixOf` info = case S8.words info of
-			(_colonsrcmode:dstmode:srcsha:dstsha:_change:[]) -> do
-				removed <- catKey (Ref srcsha) >>= \case
-					Just oldkey -> do
-						liftIO $ SQL.removeAssociatedFile oldkey
-							(asTopFilePath file)
-							(SQL.WriteHandle qh)
-						return True
-					Nothing -> return False
+			(_colonsrcmode:dstmode:srcsha:dstsha:status:[]) -> do
+				-- avoid removing associated file when
+				-- there is a merge conflict
+				removed <- if status /= "U" 
+					then catKey (Ref srcsha) >>= \case
+						Just oldkey -> do
+							liftIO $ SQL.removeAssociatedFile oldkey
+								(asTopFilePath file)
+								(SQL.WriteHandle qh)
+							return True
+						Nothing -> return False
+					else return False
 				added <- catKey (Ref dstsha) >>= \case
 					Just key -> do
 						liftIO $ SQL.addAssociatedFile key