[babl] babl-extension: print warning if no extensions were loaded

[Øyvind Kolås <ok src gnome org>]

commit 9b919537eeaa72d7d2c9fb57e6e43e3b23c04777
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Aug 31 00:17:24 2016 +0200

    babl-extension: print warning if no extensions were loaded

 babl/babl-extension.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/babl/babl-extension.c b/babl/babl-extension.c
index bc371f8..2f0b3af 100644
--- a/babl/babl-extension.c
+++ b/babl/babl-extension.c
@@ -346,6 +346,14 @@ babl_extension_load_dir_list (const char *dir_list)
         }
     }
   babl_free (path);
+  if (babl_db_count (db) <= 0)
+  {
+    fprintf (stderr,
+"WARNING: the babl installation seems broken, no extensions found in queried\n"
+"BABL_PATH (%s) this means no SIMD/instructions/special case fast paths and\n"
+"only slow reference conversions are available, applications might still\n"
+"run but software relying on babl for conversions will be slow\n", dir_list);
+  }
 }
 
 #endif