[gobject-introspection] giscanner: Don't fail on empty GTK-Doc comment blocks

[Dieter Verfaillie <dieterv src gnome org>]

commit 6b36bb4f78b7005aae8173c9c2712d7ef5d2c442
Author: Dieter Verfaillie <dieterv optionexplicit be>
Date:   Thu Jan 3 08:01:10 2013 +0100

    giscanner: Don't fail on empty GTK-Doc comment blocks
    
    A completely empty GTK-Doc comment block (/**\n*/) resulted
    in an unfriendly backtrace, complaining about an
    "AttributeError: 'NoneType' object has no attribute 'comment'"
    
    This fixes the issue and adds a test case.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=690850

 giscanner/annotationparser.py                |   25 ++++++++++++++-----------
 tests/scanner/annotationparser/gi/syntax.xml |    8 ++++++++
 2 files changed, 22 insertions(+), 11 deletions(-)
---
diff --git a/giscanner/annotationparser.py b/giscanner/annotationparser.py
index f545590..d4b2499 100644
--- a/giscanner/annotationparser.py
+++ b/giscanner/annotationparser.py
@@ -1119,20 +1119,23 @@ class AnnotationParser(object):
         ########################################################################
         # Finished parsing this comment block.
         ########################################################################
-        # We have picked up a couple of \n characters that where not
-        # intended. Strip those.
-        if comment_block.comment:
-            comment_block.comment = comment_block.comment.strip()
+        if comment_block:
+            # We have picked up a couple of \n characters that where not
+            # intended. Strip those.
+            if comment_block.comment:
+                comment_block.comment = comment_block.comment.strip()
 
-        for tag in comment_block.tags.values():
-            self._clean_comment_block_part(tag)
+            for tag in comment_block.tags.values():
+                self._clean_comment_block_part(tag)
 
-        for param in comment_block.params.values():
-            self._clean_comment_block_part(param)
+            for param in comment_block.params.values():
+                self._clean_comment_block_part(param)
 
-        # Validate and store block.
-        comment_block.validate()
-        return comment_block
+            # Validate and store block.
+            comment_block.validate()
+            return comment_block
+        else:
+            return None
 
     def _clean_comment_block_part(self, part):
         if part.comment:
diff --git a/tests/scanner/annotationparser/gi/syntax.xml b/tests/scanner/annotationparser/gi/syntax.xml
index 83c56b9..f07e4fb 100644
--- a/tests/scanner/annotationparser/gi/syntax.xml
+++ b/tests/scanner/annotationparser/gi/syntax.xml
@@ -71,6 +71,14 @@ something */</commentblock>
 
 <test>
   <!--
+  Not GTK-Doc
+  -->
+  <commentblock>/**
+*/</commentblock>
+</test>
+
+<test>
+  <!--
   Technically not GTK-Doc, but we need to support this for backwards compatibility
   -->
   <commentblock>/**