Add Merge in the contextual menus for commits and refs

PBGitRepository.h

@@ -31,6 +31,7 @@ extern NSString* PBGitRepositoryErrorDomain;
 
 - (BOOL) checkoutRefish:(id <PBGitRefish>)ref;
 - (BOOL) checkoutFiles:(NSArray *)files fromRefish:(id <PBGitRefish>)ref;
+- (BOOL) mergeWithRefish:(id <PBGitRefish>)ref;
 - (BOOL) createBranch:(NSString *)branchName atRefish:(id <PBGitRefish>)ref;
 - (BOOL) createTag:(NSString *)tagName message:(NSString *)message atRefish:(id <PBGitRefish>)commitSHA;
 - (BOOL) deleteRef:(PBGitRef *)ref;

PBGitRepository.m

@@ -474,6 +474,26 @@ NSString* PBGitRepositoryErrorDomain = @"GitXErrorDomain";
 	return YES;
 }
 
+
+- (BOOL) mergeWithRefish:(id <PBGitRefish>)ref
+{
+	NSString *refName = [ref refishName];
+
+	int retValue = 1;
+	NSArray *arguments = [NSArray arrayWithObjects:@"merge", refName, nil];
+	NSString *output = [self outputInWorkdirForArguments:arguments retValue:&retValue];
+	if (retValue) {
+		NSString *headName = [[[self headRef] ref] shortName];
+		NSString *message = [NSString stringWithFormat:@"There was an error merging %@ into %@.", refName, headName];
+		[self.windowController showErrorSheetTitle:@"Merge failed!" message:message arguments:arguments output:output];
+		return NO;
+	}
+
+	[self reloadRefs];
+	[self readCurrentBranch];
+	return YES;
+}
+
 - (BOOL) createBranch:(NSString *)branchName atRefish:(id <PBGitRefish>)ref
 {
 	if (!branchName || !ref)

PBRefController.h

@@ -24,6 +24,7 @@
 }
 
 - (void) checkout:(PBRefMenuItem *)sender;
+- (void) merge:(PBRefMenuItem *)sender;
 - (void) createBranch:(PBRefMenuItem *)sender;
 - (void) copySHA:(PBRefMenuItem *)sender;
 - (void) copyPatch:(PBRefMenuItem *)sender;

PBRefController.m

@@ -39,6 +39,15 @@
 }
 
 
+#pragma mark Merge
+
+- (void) merge:(PBRefMenuItem *)sender
+{
+	id <PBGitRefish> refish = [sender refish];
+	[historyController.repository mergeWithRefish:refish];
+}
+
+
 #pragma mark Checkout
 
 - (void) checkout:(PBRefMenuItem *)sender

PBRefMenuItem.m

@@ -39,8 +39,11 @@
 	NSMutableArray *items = [NSMutableArray array];
 
 	NSString *targetRefName = [ref shortName];
+	PBGitCommit *commit = [repo commitForRef:ref];
+	BOOL isOnHeadBranch = [commit isOnHeadBranch];
 
 	PBGitRef *headRef = [[repo headRef] ref];
+	NSString *headRefName = [headRef shortName];
 	BOOL isHead = [ref isEqualToRef:headRef];
 
 	// checkout ref
@@ -57,6 +60,11 @@
 	// view tag info
 	if ([ref isTag])
 		[items addObject:[PBRefMenuItem itemWithTitle:@"View tag info…" action:@selector(showTagInfoSheet:) enabled:YES]];
+	[items addObject:[PBRefMenuItem separatorItem]];
+
+    // merge ref
+	NSString *mergeTitle = isOnHeadBranch ? @"Merge" : [NSString stringWithFormat:@"Merge %@ into %@", targetRefName, headRefName];
+    [items addObject:[PBRefMenuItem itemWithTitle:mergeTitle action:@selector(merge:) enabled:!isOnHeadBranch]];
 
 	// delete ref
 	[items addObject:[PBRefMenuItem separatorItem]];
@@ -76,6 +84,9 @@
 {
 	NSMutableArray *items = [NSMutableArray array];
 
+	NSString *headBranchName = [[[commit.repository headRef] ref] shortName];
+	BOOL isOnHeadBranch = [commit isOnHeadBranch];
+
 	[items addObject:[PBRefMenuItem itemWithTitle:@"Checkout Commit" action:@selector(checkout:) enabled:YES]];
 	[items addObject:[PBRefMenuItem separatorItem]];
 
@@ -85,6 +96,11 @@
 
 	[items addObject:[PBRefMenuItem itemWithTitle:@"Copy SHA" action:@selector(copySHA:) enabled:YES]];
 	[items addObject:[PBRefMenuItem itemWithTitle:@"Copy Patch" action:@selector(copyPatch:) enabled:YES]];
+	[items addObject:[PBRefMenuItem separatorItem]];
+
+	// merge commit
+	NSString *mergeTitle = isOnHeadBranch ? @"Merge commit" : [NSString stringWithFormat:@"Merge commit into %@", headBranchName];
+	[items addObject:[PBRefMenuItem itemWithTitle:mergeTitle action:@selector(merge:) enabled:!isOnHeadBranch]];
 
 	for (PBRefMenuItem *item in items) {
 		[item setTarget:target];