parser fix

Author: arpruss

svgpath/parser.py

@@ -618,14 +618,29 @@ def scale(width, height, viewBox, z):
         return complex(x,y)
 
     paths = []
+
+    try:
+        width = sizeFromString(svg.attrib['width'].strip())
+    except KeyError:
+        width = None
+    try:
+        height = sizeFromString(svg.attrib['height'].strip())
+    except KeyError:
+        height = None
 
-    width = sizeFromString(svg.attrib['width'].strip())
-    height = sizeFromString(svg.attrib['height'].strip())
     try:
         viewBox = list(map(float, re.split(r'[\s,]+', svg.attrib['viewBox'].strip())))
     except KeyError:
+        if width is None or height is None:
+            raise KeyError
         viewBox = [0, 0, width*96/25.4, height*96/25.4]
 
+    if width is None:
+        width = viewBox[2] * 25.4/96
+    
+    if height is None:
+        height = viewBox[3] * 25.4/96
+        
     viewBox[2] += viewBox[0]
     viewBox[3] += viewBox[1]