[gnome-builder] code: allow uncertain content-type if there is no syntax

[Christian Hergert <chergert src gnome org>]

commit aa37baf7786e157aa9d000c69e46c1e3b38b5a0a
Author: Christian Hergert <chergert redhat com>
Date:   Fri Feb 15 12:43:35 2019 -0800

    code: allow uncertain content-type if there is no syntax
    
    This allows us to guess the syntax type, even if the guess is uncertain
    as long as there is no previous syntax set.

 src/libide/code/ide-buffer.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/src/libide/code/ide-buffer.c b/src/libide/code/ide-buffer.c
index 396815365..39cb7701e 100644
--- a/src/libide/code/ide-buffer.c
+++ b/src/libide/code/ide-buffer.c
@@ -3497,11 +3497,13 @@ ide_buffer_guess_language (IdeBuffer *self)
   else
     path = g_file_peek_path (file);
 
+  manager = gtk_source_language_manager_get_default ();
+  lang = gtk_source_buffer_get_language (GTK_SOURCE_BUFFER (self));
+
   content_type = g_content_type_guess (path, (const guchar *)line, strlen (line), &uncertain);
-  if (uncertain)
+  if (uncertain && lang != NULL)
     return;
 
-  manager = gtk_source_language_manager_get_default ();
   if (!(lang = gtk_source_language_manager_guess_language (manager, path, content_type)))
     return;