From ee6f99f204d878b01be5b17fd0d3a0f47c69d005 Mon Sep 17 00:00:00 2001
From: DreamPiggy <lizhuoli1126@126.com>
Date: Wed, 31 Oct 2018 14:40:10 +0800
Subject: [PATCH] Fix that the graphics helper method will return nil when
 scale = 0, match the UIKit behavior

---
 SDWebImage/UIImage+Transform.m | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/SDWebImage/UIImage+Transform.m b/SDWebImage/UIImage+Transform.m
index ff95ea45..a397924a 100644
--- a/SDWebImage/UIImage+Transform.m
+++ b/SDWebImage/UIImage+Transform.m
@@ -18,6 +18,10 @@
 static void *kNSGraphicsContextScaleFactorKey;
 
 static CGContextRef SDCGContextCreateBitmapContext(CGSize size, BOOL opaque, CGFloat scale) {
+    if (scale == 0) {
+        // Match `UIGraphicsBeginImageContextWithOptions`, reset to the scale factor of the device’s main screen if scale is 0.
+        scale = [NSScreen mainScreen].backingScaleFactor;
+    }
     size_t width = ceil(size.width * scale);
     size_t height = ceil(size.height * scale);
     if (width < 1 || height < 1) return NULL;
@@ -30,10 +34,6 @@ static CGContextRef SDCGContextCreateBitmapContext(CGSize size, BOOL opaque, CGF
     if (!context) {
         return NULL;
     }
-    if (scale == 0) {
-        // Match `UIGraphicsBeginImageContextWithOptions`, reset to the scale factor of the device’s main screen if scale is 0.
-        scale = [NSScreen mainScreen].backingScaleFactor;
-    }
     CGContextScaleCTM(context, scale, scale);
     
     return context;