CommitView: Add option to amend commits

PBChangedFile.h

@@ -29,9 +29,11 @@ typedef enum {
 @property (assign) BOOL hasCachedChanges;
 @property (assign) BOOL hasUnstagedChanges;
 - (NSImage *)icon;
-- (NSString *)changes;
+- (NSString *)cachedChangesAmend:(BOOL)amend;
+- (NSString *)unstagedChanges;
+
 - (void) stageChanges;
-- (void) unstageChanges;
+- (void) unstageChangesAmend:(BOOL)amend;
 
 - (id) initWithPath:(NSString *)p andRepository:(PBGitRepository *)r;
 @end

PBChangedFile.m

@@ -20,8 +20,11 @@ - (id) initWithPath:(NSString *)p andRepository:(PBGitRepository *)r
 	return self;
 }
 
-- (NSString *) cachedChanges
+- (NSString *) cachedChangesAmend:(BOOL) amend
 {
+	if (amend)
+		return [repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", @"--cached", @"HEAD^", @"--", path, nil]];
+
 	return [repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", @"--cached", @"--", path, nil]];
 }
 
@@ -63,9 +66,12 @@ - (void) stageChanges
 	self.hasCachedChanges = YES;
 }
 
-- (void) unstageChanges
+- (void) unstageChangesAmend:(BOOL) amend
 {
-	[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"reset", @"--", path, nil]];
+	if (amend)
+		[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"reset", @"HEAD^", @"--", path, nil]];
+	else
+		[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"reset", @"--", path, nil]];
 	self.hasCachedChanges = NO;
 	self.hasUnstagedChanges = YES;
 }

PBGitCommitController.h

@@ -23,6 +23,7 @@
 	// You can increase it when your process start
 	// And decrease it after you have finished.
 	int busy;
+	BOOL amend;
 
 	IBOutlet PBIconAndTextCell* unstagedButtonCell;
 	IBOutlet PBIconAndTextCell* cachedButtonCell;
@@ -34,6 +35,7 @@
 @property (retain) NSMutableArray *files;
 @property (copy) NSString *status;
 @property (assign) int busy;
+@property (assign) BOOL amend;
 
 - (void) readCachedFiles:(NSNotification *)notification;
 - (void) readOtherFiles:(NSNotification *)notification;

PBGitCommitController.m

@@ -12,13 +12,15 @@
 
 @implementation PBGitCommitController
 
-@synthesize files, status, busy;
+@synthesize files, status, busy, amend;
 
 - (void)awakeFromNib
 {
 	[super awakeFromNib];
 	self.busy = 0;
 
+	amend = NO;
+
 	[unstagedButtonCell setAction:@selector(rowClicked:)];
 	[cachedButtonCell setAction:@selector(rowClicked:)];
 
@@ -39,6 +41,18 @@ - (void)awakeFromNib
 		[[NSSortDescriptor alloc] initWithKey:@"path" ascending:true]]];
 }
 
+- (void) setAmend:(BOOL)newAmend
+{
+	if (newAmend == amend)
+		return;
+	amend = newAmend;
+
+	if (amend && [[commitMessageView string] length] <= 3)
+		commitMessageView.string = [repository outputForCommand:@"log -1 --pretty=format:%s%n%n%b HEAD"];
+
+	[self refresh:self];
+}
+
 - (NSArray *) linesFromNotification:(NSNotification *)notification
 {
 	NSDictionary *userInfo = [notification userInfo];
@@ -60,16 +74,18 @@ - (NSArray *) linesFromNotification:(NSNotification *)notification
 
 - (NSString *) parentTree
 {
-	id a = [repository parseReference:@"HEAD"];
+	NSString *parent = amend ? @"HEAD^" : @"HEAD";
+
+	NSString *a = [repository parseReference:@"HEAD^"];
 
 	// TODO: parseReference should exit nil if it errors out. For
 	// now, compare to "HEAD"
-	if ([a isEqualToString:@"HEAD"]) {
+	if ([a isEqualToString:parent]) {
 		// We don't have a head ref. Return the empty tree.
 		return @"4b825dc642cb6eb9a060e54bf8d69288fbee4904";
 	}
 
-	return @"HEAD";
+	return parent;
 }
 
 - (void) refresh:(id) sender
@@ -233,9 +249,10 @@ - (IBAction) commit:(id) sender
 	int ret;
 
 	NSMutableArray *arguments = [NSMutableArray arrayWithObjects:@"commit-tree", tree, nil];
-	if ([repository parseSymbolicReference:@"HEAD"]) {
+	NSString *parent = amend ? @"HEAD^" : @"HEAD";
+	if ([repository parseReference:parent]) {
 		[arguments addObject:@"-p"];
-		[arguments addObject:@"HEAD"];
+		[arguments addObject:parent];
 	}
 
 	NSString *commit = [repository outputForArguments:arguments
@@ -259,7 +276,9 @@ - (IBAction) commit:(id) sender
 	repository.hasChanged = YES;
 	self.busy--;
 	[commitMessageView setString:@""];
+	amend = NO;
 	[self refresh:self];
+	self.amend = NO;
 }
 
 - (void) tableClicked:(NSTableView *) tableView
@@ -280,7 +299,7 @@ - (void) tableClicked:(NSTableView *) tableView
 	if ([tableView tag] == 0)
 		[selectedItem stageChanges];
 	else
-		[selectedItem unstageChanges];
+		[selectedItem unstageChangesAmend:amend];
 
 	// Add the file to the other controller if it's not there yet
 	for (PBChangedFile *object in [otherController arrangedObjects])