From 4491d1e1674dea4d8d988b770e91c5fd5bce94fb Mon Sep 17 00:00:00 2001
From: monsieurtanuki <fabrice_fontaine@hotmail.com>
Date: Tue, 7 May 2024 12:32:09 +0200
Subject: [PATCH] fix: 1874 - fixed side-effect crash for final dot / final
 dash (#1875)

---
 .../layer/misc/line_patterns/pixel_hiker.dart | 22 ++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/lib/src/layer/misc/line_patterns/pixel_hiker.dart b/lib/src/layer/misc/line_patterns/pixel_hiker.dart
index f0c7baa4c..4eb4efb05 100644
--- a/lib/src/layer/misc/line_patterns/pixel_hiker.dart
+++ b/lib/src/layer/misc/line_patterns/pixel_hiker.dart
@@ -52,9 +52,13 @@ class DottedPixelHiker extends _PixelHiker {
     // side-effect of the last dot
     if (!closePath) {
       if (patternFit != PatternFit.none) {
-        final last = result.last;
-        if (last != offsets.last) {
+        if (result.isEmpty) {
           addVisibleOffset(offsets.last);
+        } else {
+          final last = result.last;
+          if (last != offsets.last) {
+            addVisibleOffset(offsets.last);
+          }
         }
       }
     }
@@ -157,9 +161,17 @@ class DashedPixelHiker extends _PixelHiker {
         }
       } else if (patternFit == PatternFit.extendFinalDash) {
         final lastOffset = closePath ? offsets.first : offsets.last;
-        final lastVisible = result.last.end;
-        if (lastOffset != lastVisible) {
-          result.add(VisibleSegment(lastVisible, lastOffset));
+        if (result.isEmpty) {
+          if (offsets.length >= 2) {
+            final beforeLastOffset =
+                offsets[closePath ? offsets.length - 1 : offsets.length - 2];
+            result.add(VisibleSegment(beforeLastOffset, lastOffset));
+          }
+        } else {
+          final lastVisible = result.last.end;
+          if (lastOffset != lastVisible) {
+            result.add(VisibleSegment(lastVisible, lastOffset));
+          }
         }
       }
     }