Multiple changes to -selectCommit: from PBGitHistoryController.

- Change return type from void to BOOL to convey if selecting succeeded 
  or not.

- Return NO if the cliArgs from sharedApplicationController contain "--commit",
  since then we need to just show the commit stage. Updating the commit list
  selection is not necessary. In fact, it will confuse order among consequent 
  calls.

- If the oldIndex equals NSNotFound, try to get the index of the currently 
  selected object by finding it among the content object of the commitController.
  
  If we find it we save the result in an ivar called selectedCommit so that 
  subsequent calls will always have this available as an alternative back-up
  plan.

PBGitHistoryController.h

@@ -71,11 +71,12 @@
 - (IBAction) setDetailedView:(id)sender;
 - (IBAction) setTreeView:(id)sender;
 - (IBAction) setBranchFilter:(id)sender;
-
-- (void) selectCommit: (NSString*) commit;
 - (IBAction) refresh:(id)sender;
 - (IBAction) toggleQLPreviewPanel:(id)sender;
 - (IBAction) openSelectedFile:(id)sender;
+
+- (BOOL) selectCommit: (NSString*) commit;
+
 - (void) updateQuicklookForce: (BOOL) force;
 
 

PBGitHistoryController.m

@@ -424,18 +424,32 @@
 	return selectedCommits;
 }
 
-- (void) selectCommit:(NSString *)commitSHA
+- (BOOL) selectCommit:(NSString *)commitSHA
 {
+    ApplicationController * appController = [ApplicationController sharedApplicationController];
+    if (appController.launchedFromGitx && [appController.cliArgs isEqualToString:@"--commit"]) {
+        return NO;
+    }
+    NSLog(@"[%@ %s]: SHA = %@", [self class], _cmd, commitSHA);
 	if (!forceSelectionUpdate && [[selectedCommit realSha] isEqualToString:commitSHA])
-		return;
+		return NO;
 
 	NSInteger oldIndex = [[commitController selectionIndexes] firstIndex];
+    if (oldIndex == NSNotFound) {
+        oldIndex = [[commitController content] indexOfObject:selectedCommit];
+    }
 
 	NSArray *selectedCommits = [self selectedObjectsForSHA:commitSHA];
+    selectedCommit = [selectedCommits objectAtIndex:0];
+
 	[commitController setSelectedObjects:selectedCommits];
 
-	if (repository.currentBranchFilter != kGitXSelectedBranchFilter)
-		[self scrollSelectionToTopOfViewFrom:oldIndex];
+	if (repository.currentBranchFilter != kGitXSelectedBranchFilter) {
+        NSLog(@"[%@ %s] currentBranchFilter = %@", [self class], _cmd, PBStringFromBranchFilterType(repository.currentBranchFilter));
+        [self scrollSelectionToTopOfViewFrom:oldIndex];
+    }
+
+    return YES;
 }
 
 - (BOOL) hasNonlinearPath