Fix Doxyfile parsing when the first tag occurs on the first line.

Also, add a couple of regression tests.

doxygen.py

@@ -58,9 +58,9 @@ def DoxyfileParse(file_contents):
 
    lineno = lex.lineno
    token = lex.get_token()
-   key = token   # the first token should be a key
+   key = None
    last_token = ""
-   key_token = False
+   key_token = True # the first token should be a key
    next_key = False
    new_data = True
 

test.py

@@ -0,0 +1,26 @@
+#!/usr/bin/python
+#
+# tests for scons doxygen builder
+#
+
+import unittest
+import os
+import sys
+from doxygen import DoxyfileParse
+
+class TestParser(unittest.TestCase):
+    def testSimpleParse(self):
+        text="""
+INPUT  = test.h
+"""
+        result = DoxyfileParse(text)
+        self.assertEqual(["test.h"], result["INPUT"])
+
+    def testParseTagOnFirstLine(self):
+        text="""INPUT=."""
+        result = DoxyfileParse(text)
+        self.assertEqual(["."], result["INPUT"])
+
+
+if __name__ == '__main__':
+    unittest.main()