fix nullable issues

Author: arielelkin

Sources/SVGBezierPath.mm

@@ -29,18 +29,24 @@ + (void)resetCache
 {
     NSArray<SVGBezierPath*> *paths = [self.class._svg_pathCache objectForKey:aURL];
     if (!paths) {
-        paths =  [self pathsFromSVGString:[NSString stringWithContentsOfURL:aURL
-                                                               usedEncoding:NULL
-                                                                      error:NULL]];
-        if (paths) {
-            [self.class._svg_pathCache setObject:paths forKey:aURL];
+        NSString * const svgString = [NSString stringWithContentsOfURL:aURL
+                                                           usedEncoding:NULL
+                                                                  error:NULL];
+        paths =  [self pathsFromSVGString:svgString];
+        if (!paths) {
+            paths = @[];
         }
+        [self.class._svg_pathCache setObject:paths forKey:aURL];
     }
-    return [[NSArray alloc] initWithArray:paths copyItems:YES];
+    NSArray<SVGBezierPath*> * const safePaths = paths ?: @[];
+    return [[NSArray alloc] initWithArray:safePaths copyItems:YES];
 }
 
 + (NSArray<SVGBezierPath*> *)pathsFromSVGString:(NSString * const)svgString
 {
+    if (svgString.length == 0) {
+        return @[];
+    }
     SVGAttributeSet *cgAttrs;
     NSArray * const pathRefs = CGPathsFromSVGString(svgString, &cgAttrs);
     NSMutableArray<SVGBezierPath*> * const paths = [NSMutableArray arrayWithCapacity:pathRefs.count];
@@ -67,7 +73,7 @@ - (instancetype)copyWithZone:(NSZone *)zone
     return copy;
 }
 
-- (SVGBezierPath *)pathBySettingSVGAttributes:(NSDictionary *)attributes
+- (nullable SVGBezierPath *)pathBySettingSVGAttributes:(NSDictionary *)attributes
 {
     NSParameterAssert(attributes);
 

Sources/SVGEngine.mm

@@ -442,7 +442,7 @@ @interface SVGAttributeSet () {
 }
 
 /// This parses a single isolated path. creating a cgpath from just a string formatted like the d element in a path
-CGPathRef CGPathFromSVGPathString(NSString *svgString) {
+CGPathRef CGPathFromSVGPathString(NSString *svgString) CF_RETURNS_RETAINED {
     CGPathRef const path = pathDefinitionParser(svgString).parse();
     if(!path) {
         NSLog(@"*** Error: Invalid path attribute");

Sources/include/SVGBezierPath.h

@@ -63,7 +63,7 @@ FOUNDATION_EXTERN void SVGDrawPathsWithBlock(NSArray<SVGBezierPath*> * const pat
  * @param attributes A dictionary of SVG attributes to set.
  *
  */
-- (SVGBezierPath *)pathBySettingSVGAttributes:(NSDictionary *)attributes;
+- (nullable SVGBezierPath *)pathBySettingSVGAttributes:(NSDictionary *)attributes;
 
 /*!
  * @brief The value of the SVG's viewBox attribute, expressed as a CGRect. If there is

Sources/include/SVGEngine.h

@@ -36,7 +36,7 @@ NSArray *CGPathsFromSVGString(NSString *svgString, SVGAttributeSet **attributes)
  * @return A single CGPathRef object
  *
  */
-CGPathRef CGPathFromSVGPathString(NSString *svgString);
+CGPathRef CGPathFromSVGPathString(NSString *svgString) CF_RETURNS_RETAINED;
 
 /*!
  * @brief Returns SVG representing `paths`

Sources/include/SVGImageView.h

@@ -42,15 +42,15 @@ IB_DESIGNABLE
  * @discussion Setting this property solidly fills the shape formed by the SVG path with the given color.
  *
  */
-@property(nonatomic, copy) IBInspectable PSVGColor *fillColor;
+@property(nonatomic, copy, nullable) IBInspectable PSVGColor *fillColor;
 
 
 /*!
  * @brief The color to stroke the path with.
  * @discussion Setting this property solidly colors the path generated by the SVG file.
  *
  */
-@property(nonatomic, copy) IBInspectable PSVGColor *strokeColor;
+@property(nonatomic, copy, nullable) IBInspectable PSVGColor *strokeColor;
 
 
 /*!