Try to fit larger ints

Author: bstorm

adafruit_imageload/pnm/__init__.py

@@ -63,7 +63,16 @@ def load(f, header, *, bitmap=None, palette=None):
                 if next_byte == b"\n":
                     break
         if next_byte.isdigit():
-            pnm_header.append(int(next_byte))
+            value = b""
+            while True:
+                if not next_byte.isdigit():
+                    break
+                value += next_byte
+                next_byte = f.read(1)
+                if not next_byte:
+                    raise RuntimeError("Unsupported image format")
+
+            pnm_header.append(int.from_bytes(value, "big"))
             continue
 
         if not next_byte: