[gtk-doc] common: be more verbose for file updates

[Stefan Sauer <stefkost src gnome org>]

commit 2c19526a0bce5fa035b9d24765784d93eeaf775b
Author: Stefan Sauer <ensonic users sf net>
Date:   Wed Aug 9 11:03:05 2017 +0200

    common: be more verbose for file updates

 gtkdoc/common.py |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtkdoc/common.py b/gtkdoc/common.py
index 09e7bc0..470722e 100644
--- a/gtkdoc/common.py
+++ b/gtkdoc/common.py
@@ -74,6 +74,7 @@ def UpdateFileIfChanged(old_file, new_file, make_backup):
         new_contents = open(new_file, 'rb').read()
         if old_contents == new_contents:
             os.unlink(new_file)
+            logging.debug("-> content is the same.")
             return False
 
         if make_backup:
@@ -83,6 +84,9 @@ def UpdateFileIfChanged(old_file, new_file, make_backup):
             os.rename(old_file, backupname)
         else:
             os.unlink(old_file)
+        logging.debug("-> content differs.")
+    else:
+        logging.debug("-> %s created.", old_file)
 
     os.rename(new_file, old_file)
     return True