Highlight mark in red if it has an error code. Issue 4504.

sources/PTYSession.m

@@ -3736,7 +3736,7 @@ ITERM_WEAKLY_REFERENCEABLE
         self.currentMarkOrNotePosition = mark.entry.interval;
         offset += [_screen totalScrollbackOverflow];
         [_textview scrollToAbsoluteOffset:offset height:[_screen height]];
-        [_textview highlightMarkOnLine:VT100GridRangeMax(range)];
+        [_textview highlightMarkOnLine:VT100GridRangeMax(range) hasErrorCode:NO];
     }
 }
@@ -4157,7 +4157,13 @@ ITERM_WEAKLY_REFERENCEABLE
 - (void)highlightMarkOrNote:(id<IntervalTreeObject>)obj {
     if ([obj isKindOfClass:[iTermMark class]]) {
-        [_textview highlightMarkOnLine:VT100GridRangeMax([_screen lineNumberRangeOfInterval:obj.entry.interval])];
+        BOOL hasErrorCode = NO;
+        if ([obj isKindOfClass:[VT100ScreenMark class]]) {
+            VT100ScreenMark *mark = (VT100ScreenMark *)obj;
+            hasErrorCode = mark.code != 0;
+        }
+        [_textview highlightMarkOnLine:VT100GridRangeMax([_screen lineNumberRangeOfInterval:obj.entry.interval])
+                          hasErrorCode:hasErrorCode];
     } else {
         PTYNoteViewController *note = (PTYNoteViewController *)obj;
         [note setNoteHidden:NO];

sources/PTYTextView.h

@@ -441,7 +441,7 @@ typedef void (^PTYTextViewDrawingHookBlock)(iTermTextDrawingHelper *);
 - (void)updateNoteViewFrames;
 // Show a visual highlight of a mark on the given line number.
-- (void)highlightMarkOnLine:(int)line;
+- (void)highlightMarkOnLine:(int)line hasErrorCode:(BOOL)hasErrorCode;
 - (IBAction)installShellIntegration:(id)sender;

sources/PTYTextView.m

@@ -5254,23 +5254,23 @@ static double EuclideanDistance(NSPoint p1, NSPoint p2) {
     }
 }
-- (void)highlightMarkOnLine:(int)line {
+- (void)highlightMarkOnLine:(int)line hasErrorCode:(BOOL)hasErrorCode {
     CGFloat y = line * _lineHeight;
-    NSView *blue = [[[NSView alloc] initWithFrame:NSMakeRect(0, y, self.frame.size.width, _lineHeight)] autorelease];
-    [blue setWantsLayer:YES];
-    [self addSubview:blue];
+    NSView *highlightingView = [[[NSView alloc] initWithFrame:NSMakeRect(0, y, self.frame.size.width, _lineHeight)] autorelease];
+    [highlightingView setWantsLayer:YES];
+    [self addSubview:highlightingView];
     // Set up layer's initial state
-    blue.layer.backgroundColor = [[NSColor blueColor] CGColor];
-    blue.layer.opaque = NO;
-    blue.layer.opacity = 0.75;
+    highlightingView.layer.backgroundColor = hasErrorCode ? [[NSColor redColor] CGColor] : [[NSColor blueColor] CGColor];
+    highlightingView.layer.opaque = NO;
+    highlightingView.layer.opacity = 0.75;
     // Animate it out, removing from superview when complete.
     [CATransaction begin];
-    [blue retain];
+    [highlightingView retain];
     [CATransaction setCompletionBlock:^{
-        [blue removeFromSuperview];
-        [blue release];
+        [highlightingView removeFromSuperview];
+        [highlightingView release];
     }];
     const NSTimeInterval duration = 0.75;
@@ -5281,7 +5281,7 @@ static double EuclideanDistance(NSPoint p1, NSPoint p2) {
     animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
     animation.removedOnCompletion = NO;
     animation.fillMode = kCAFillModeForwards;
-    [blue.layer addAnimation:animation forKey:@"opacity"];
+    [highlightingView.layer addAnimation:animation forKey:@"opacity"];
     [CATransaction commit];
 }