write output using encoding flag, harden regex

Author: hbmartin

graphviz2drawio/__main__.py

@@ -44,7 +44,7 @@ def _convert_file(
             with to_convert.open(encoding=encoding) as contents:
                 output = convert(contents.read(), program)
     except UnicodeDecodeError:
-        if encoding != UTF8 and isinstance(to_convert, Path):
+        if encoding.lower() != UTF8 and isinstance(to_convert, Path):
             # Attempt to automatically recover for file. Chinese Windows systems in
             # particular often use other encodings e.g. gbk, cp950, cp1252, etc. but
             # the actual dot files are still UTF-8 encoded
@@ -68,7 +68,7 @@ def _convert_file(
 
     out_path = Path(outfile)
     out_path.parent.mkdir(parents=True, exist_ok=True)
-    out_path.write_text(output)
+    out_path.write_text(output, encoding=encoding)
     stderr.write("Converted file: " + outfile + "\n")
     return None
 

graphviz2drawio/graphviz2drawio.py

@@ -59,8 +59,8 @@ def _load_pygraphviz_graph(
         # is mistakenly identified as a filename.
         # https://github.com/pygraphviz/pygraphviz/issues/536
         pattern = re.compile(
-            pattern=r"^\s*(strict)?\s*(graph|digraph).*{",
-            flags=re.DOTALL | re.MULTILINE,
+            pattern=r"^(?=(\s*))\1(strict)?(?=(\s*))\3(graph|digraph)[^{]*{",
+            flags=re.MULTILINE,
         )
         if pattern.search(graph_to_convert):
             return AGraph(string=graph_to_convert)