PBGitCommitController: retain author information of previous commit

PBGitCommitController.h

@@ -30,6 +30,7 @@
 	// And decrease it after you have finished.
 	int busy;
 	BOOL amend;
+	NSDictionary *amendEnvironment;
 
 }
 

PBGitCommitController.m

@@ -10,6 +10,7 @@
 #import "NSFileHandleExt.h"
 #import "PBChangedFile.h"
 #import "PBWebChangesController.h"
+#import "NSString_RegEx.h"
 
 
 @interface PBGitCommitController (PrivateMethods)
@@ -51,20 +52,34 @@
 {
 	if (newAmend == amend)
 		return;
+
 	amend = newAmend;
+	amendEnvironment = nil;
 
-	// Replace commit message with the old one if it's less than 3 characters long.
-	// This is just a random number.
-	if (amend && [[commitMessageView string] length] <= 3) {
+	// If we amend, we want to keep the author information for the previous commit
+	// We do this by reading in the previous commit, and storing the information
+	// in a dictionary. This dictionary will then later be read by [self commit:]
+	if (amend) {
 		NSString *message = [repository outputForCommand:@"cat-file commit HEAD"];
-		NSRange r = [message rangeOfString:@"\n\n"];
-		if (r.location != NSNotFound)
-			message = [message substringFromIndex:r.location + 2];
+		NSArray *match = [message substringsMatchingRegularExpression:@"\nauthor ([^\n]*) <([^\n>]*)> ([0-9]+[^\n]*)\n" count:3 options:0 ranges:nil error:nil];
+		if (match)
+			amendEnvironment = [NSDictionary dictionaryWithObjectsAndKeys:[match objectAtIndex:1], @"GIT_AUTHOR_NAME",
+				[match objectAtIndex:2], @"GIT_AUTHOR_EMAIL",
+				[match objectAtIndex:3], @"GIT_AUTHOR_DATE",
+				 nil];
 
-		commitMessageView.string = message;
+		// Replace commit message with the old one if it's less than 3 characters long.
+		// This is just a random number.
+		if ([[commitMessageView string] length] <= 3) {
+			// Find the commit message
+			NSRange r = [message rangeOfString:@"\n\n"];
+			if (r.location != NSNotFound)
+				message = [message substringFromIndex:r.location + 2];
+
+			commitMessageView.string = message;
+		}
 	}
 
-
 	[self refresh:self];
 }
 
@@ -336,6 +351,7 @@
 
 	NSString *commit = [repository outputForArguments:arguments
 										  inputString:commitMessage
+							   byExtendingEnvironment:amendEnvironment
 											 retValue: &ret];
 
 	if (ret || [commit length] != 40)
@@ -361,6 +377,7 @@
 	self.busy--;
 	[commitMessageView setString:@""];
 	amend = NO;
+	amendEnvironment = nil;
 	[self refresh:self];
 	self.amend = NO;
 }