From f593f6efa0e16fb5f307ec63402ac542a5de2fce Mon Sep 17 00:00:00 2001
From: Robert Sesek <rsesek@bluestatic.org>
Date: Sun, 8 Dec 2019 13:42:32 -0500
Subject: [PATCH] Fix crashes in BSLineNumberRulerView when the lineIndex_ is
 empty.

This may happen if file access is not granted and source files cannot be
read.
---
 Source/BSLineNumberRulerView.mm | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/Source/BSLineNumberRulerView.mm b/Source/BSLineNumberRulerView.mm
index b530bf0..f40e94b 100644
--- a/Source/BSLineNumberRulerView.mm
+++ b/Source/BSLineNumberRulerView.mm
@@ -142,10 +142,14 @@ const CGFloat kRulerRightPadding = 2.5;
   [self computeLineIndex];
 
   // Determine the width of the ruler based on the line count.
-  NSUInteger lastElement = lineIndex_.back() + 1;
-  NSAttributedString* lastElementString = [self attributedStringForLineNumber:lastElement];
-  NSSize boundingSize = [lastElementString size];
-  [self setRuleThickness:std::max(kDefaultWidth, boundingSize.width)];
+  if (lineIndex_.empty()) {
+    [self setRuleThickness:kDefaultWidth];
+  } else {
+    NSUInteger lastElement = lineIndex_.back() + 1;
+    NSAttributedString* lastElementString = [self attributedStringForLineNumber:lastElement];
+    NSSize boundingSize = [lastElementString size];
+    [self setRuleThickness:std::max(kDefaultWidth, boundingSize.width)];
+  }
 
   [self setNeedsDisplay:YES];
 }
@@ -209,6 +213,9 @@ const CGFloat kRulerRightPadding = 2.5;
     index = NSMaxRange([text lineRangeForRange:NSMakeRange(index, 0)]);
   }
 
+  if (lineIndex_.empty())
+    return;
+
   NSUInteger lineEnd, contentEnd;
   [text getLineStart:NULL
                  end:&lineEnd
-- 
2.43.5