Fix crashes with mypaint codebase

pyment/docstring.py

@@ -987,6 +987,7 @@ def _extra_tagstyle_elements(self, data):
                     param_part, param_description = line.split(':', 1)
                 else:
                     print("WARNING: malformed docstring parameter")
+                    continue
                 res = re.split(r'\s+', param_part.strip())
                 if len(res) == 1:
                     param_name = res[0].strip()
@@ -1032,9 +1033,15 @@ def _extra_tagstyle_elements(self, data):
             else:
                 # suppose to be line of a multiline element
                 if last_element['nature'] == 'param':
-                    ret[last_element['name']]['description'] += f"\n{line}"
+                    if ret[last_element['name']]['description'] is None:
+                        ret[last_element['name']]['description'] = line
+                    else:
+                        ret[last_element['name']]['description'] += f"\n{line}"
                 elif last_element['nature'] == 'type':
-                    ret[last_element['name']]['description'] += f"\n{line}"
+                    if ret[last_element['name']]['description'] is None:
+                        ret[last_element['name']]['description'] = line
+                    else:
+                        ret[last_element['name']]['description'] += f"\n{line}"
         return ret
 
     def _extract_not_tagstyle_old_way(self, data):

tests/mypaint.py

@@ -0,0 +1,12 @@
+def func1(param1):
+    """
+    :param param1:
+        foo bar
+    """
+    pass
+
+def func2(param1):
+    """
+    :param float param2; foo bar
+    """
+    pass

tests/mypaint.py.patch

@@ -0,0 +1,21 @@
+--- a/mypaint.py
++++ b/mypaint.py
+@@ -1,12 +1,15 @@
+ def func1(param1):
+     """
+-    :param param1:
+-        foo bar
++
++    :param param1: foo bar
++
+     """
+     pass
+
+ def func2(param1):
+     """
+-    :param float param2; foo bar
++
++    :param param1: 
++
+     """
+     pass

tests/test_issues.py

@@ -307,6 +307,15 @@ def testIssue99(self):
         f.close()
         self.assertEqual(''.join(p.diff()), patch)
 
+    def testMypaint(self):
+        # Title: Crash when multiline description starts on next line
+        p = pym.PyComment(absdir('mypaint.py'))
+        p._parse()
+        f = open(absdir('mypaint.py.patch'))
+        patch = f.read()
+        f.close()
+        self.assertEqual(''.join(p.diff()), patch)
+
 
 def main():
     unittest.main()