giscanner: fix c0e748e1cdf8cf0803266f94c3c5ad154df504a8

When encountering /**/ in the source, parse_gtk_doc_comment()
would be executed (due to the /** part starting a GTK-Doc
comment block) and would happily consume the / and everything
up until the next comment block was closed or EOF, thus
consuming a whole block of C code...

Encoutered in the wild here:
https://git.gnome.org/browse/clutter-gst/tree/clutter-gst/clutter-gst-player.c?id=03f0d8f48bd7f60e582e6185cb73a07038e8d55d#n1926

3 files changed, 52 insertions, 51 deletions

diff --git a/giscanner/annotationparser.py b/giscanner/annotationparser.py
index 244df114..a00bac1d 100644
--- a/giscanner/annotationparser.py
+++ b/giscanner/annotationparser.py
@@ -294,8 +294,9 @@ COMMENT_BLOCK_START_RE = re.compile(
     ^                                                    # start
     (?P<code>.*?)                                        # whitespace, code, ...
     \s*                                                  # 0 or more whitespace characters
-    (?P<token>/\*{2}(?!\*))                              # 1 forward slash character followed
+    (?P<token>/\*{2}(?![\*/]))                           # 1 forward slash character followed
                                                          #   by exactly 2 asterisk characters
+                                                         #   and not followed by a slash character
     \s*                                                  # 0 or more whitespace characters
     (?P<comment>.*?)                                     # GTK-Doc comment text
     \s*                                                  # 0 or more whitespace characters
diff --git a/giscanner/scannerlexer.l b/giscanner/scannerlexer.l
index 554e2da7..bf51d0d5 100644
--- a/giscanner/scannerlexer.l
+++ b/giscanner/scannerlexer.l
@@ -46,7 +46,6 @@ char linebuf[2000];
 extern int yylex (GISourceScanner *scanner);
 #define YY_DECL int yylex (GISourceScanner *scanner)
 static int yywrap (void);
-static void parse_gtk_doc_comment (GISourceScanner *scanner);
 static void parse_comment (GISourceScanner *scanner);
 static void parse_trigraph (GISourceScanner *scanner);
 static void process_linemarks (GISourceScanner *scanner);
@@ -75,7 +74,6 @@ stringtext				([^\\\"])|(\\.)
 
 [\t\f\v\r ]+				{ /* Ignore whitespace. */ }
 
-"/**"					{ parse_gtk_doc_comment(scanner); }
 "/*"					{ parse_comment(scanner); }
 "/*"[\t ]?<[\t ,=A-Za-z0-9_]+>[\t ]?"*/" { parse_trigraph(scanner); }
 "//".*					{ /* Ignore C++ style comments. */ }
@@ -224,72 +222,72 @@ yywrap (void)
 }
 
 static void
-parse_gtk_doc_comment (GISourceScanner *scanner)
+parse_comment (GISourceScanner *scanner)
 {
-  GString *string = NULL;
   int c1, c2;
+  GString *string = NULL;
   GISourceComment *comment;
   int comment_lineno;
   int skip = FALSE;
 
-  if (!g_list_find_custom (scanner->filenames,
-                           scanner->current_filename,
-                           (GCompareFunc)g_strcmp0)) {
-      skip = TRUE;
-  } else {
-      string = g_string_new (yytext);
-  }
-
   c1 = input();
   c2 = input();
 
-  comment_lineno = lineno;
-
-  while (c2 != EOF && !(c1 == '*' && c2 == '/'))
-    {
-      if (!skip)
-        g_string_append_c (string, c1);
-
-      if (c1 == '\n')
-        lineno++;
-
-      c1 = c2;
-      c2 = input();
+  if (c2 != EOF && (c1 == '*' && c2 != '*' && c2 != '/')) {
+    /*
+     * Store GTK-Doc comment blocks,
+     * starts with one '/' followed by exactly two '*' and not followed by a '/'
+     */
+    if (!g_list_find_custom (scanner->filenames,
+                             scanner->current_filename,
+                             (GCompareFunc)g_strcmp0)) {
+        skip = TRUE;
+    } else {
+        string = g_string_new (yytext);
     }
 
-  if (skip) {
-      return;
-  }
-
-  g_string_append (string, "*/");
+    comment_lineno = lineno;
 
-  comment = g_slice_new (GISourceComment);
-  comment->comment = g_string_free (string, FALSE);
-  comment->line = comment_lineno;
-  comment->filename = g_strdup(scanner->current_filename);
+    while (c2 != EOF && !(c1 == '*' && c2 == '/'))
+      {
+        if (!skip)
+          g_string_append_c (string, c1);
 
-  scanner->comments = g_slist_prepend (scanner->comments,
-                                       comment);
-}
+        if (c1 == '\n')
+          lineno++;
 
-static void
-parse_comment (GISourceScanner *scanner)
-{
-  int c1, c2;
+        c1 = c2;
+        c2 = input();
+      }
 
-  c1 = input();
-  c2 = input();
+    if (skip) {
+        return;
+    }
 
-  while (c2 != EOF && !(c1 == '*' && c2 == '/'))
-    {
-      if (c1 == '\n')
-        lineno++;
+    g_string_append (string, "*/");
 
-      c1 = c2;
-      c2 = input();
-    }
+    comment = g_slice_new (GISourceComment);
+    comment->comment = g_string_free (string, FALSE);
+    comment->line = comment_lineno;
+    comment->filename = g_strdup(scanner->current_filename);
 
-  return;
+    scanner->comments = g_slist_prepend (scanner->comments,
+                                         comment);
+  } else {
+    /*
+     * Ignore all other comment blocks
+     */
+    while (c2 != EOF && !(c1 == '*' && c2 == '/'))
+      {
+        if (c1 == '\n')
+          lineno++;
+
+        c1 = c2;
+        c2 = input();
+      }
+
+    return;
+  }
 }
 
 static int
diff --git a/tests/scanner/annotationparser/test_patterns.py b/tests/scanner/annotationparser/test_patterns.py
index ed687a43..d5da82b6 100644
--- a/tests/scanner/annotationparser/test_patterns.py
+++ b/tests/scanner/annotationparser/test_patterns.py
@@ -84,6 +84,8 @@ comment_start_tests = [
          None),
     (COMMENT_BLOCK_START_RE, ' /*****xyz',
          None),
+    (COMMENT_BLOCK_START_RE, ' /**/',
+         None),
 ]