[gtk/wip/baedert/fix-gl-debug: 1/2] gdkglcontext: Limit gl debug label length

[Timm Bäder <baedert src gnome org>]

commit 6f3e6083314b39d759871e59212ce41ea64c173b
Author: Timm Bäder <mail baedert org>
Date:   Sat Apr 27 09:49:41 2019 +0200

    gdkglcontext: Limit gl debug label length
    
    There's a maximum length we have to adhere to, otherwise GL throws a
    GL_INVALID_VALUE error.

 gdk/gdkglcontext.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)
---
diff --git a/gdk/gdkglcontext.c b/gdk/gdkglcontext.c
index 3f93d83f42..b36b721f49 100644
--- a/gdk/gdkglcontext.c
+++ b/gdk/gdkglcontext.c
@@ -116,6 +116,8 @@ typedef struct {
 
   int use_es;
 
+  int max_debug_label_length;
+
   GdkGLContextPaintData *paint_data;
 } GdkGLContextPrivate;
 
@@ -457,11 +459,14 @@ gdk_gl_context_push_debug_group_printf (GdkGLContext *context,
 
   if (priv->use_khr_debug)
     {
+      int msg_len;
+
       va_start (args, format);
       message = g_strdup_vprintf (format, args);
       va_end (args);
 
-      glPushDebugGroupKHR (GL_DEBUG_SOURCE_APPLICATION, 0, -1, message);
+      msg_len = MIN (priv->max_debug_label_length, strlen (message) - 1);
+      glPushDebugGroupKHR (GL_DEBUG_SOURCE_APPLICATION, 0, msg_len, message);
       g_free (message);
     }
 }
@@ -500,11 +505,15 @@ gdk_gl_context_label_object_printf  (GdkGLContext *context,
 
   if (priv->use_khr_debug)
     {
+      int msg_len;
+
       va_start (args, format);
       message = g_strdup_vprintf (format, args);
       va_end (args);
 
-      glObjectLabel (identifier, name, -1, message);
+      msg_len = MIN (priv->max_debug_label_length, strlen (message) - 1);
+
+      glObjectLabel (identifier, name, msg_len, message);
       g_free (message);
     }
 }
@@ -992,7 +1001,10 @@ gdk_gl_context_check_extensions (GdkGLContext *context)
   display = gdk_draw_context_get_display (GDK_DRAW_CONTEXT (context));
 
   if (priv->has_khr_debug && GDK_DISPLAY_DEBUG_CHECK (display, GL_DEBUG))
-    priv->use_khr_debug = TRUE;
+    {
+      priv->use_khr_debug = TRUE;
+      glGetIntegerv (GL_MAX_LABEL_LENGTH, &priv->max_debug_label_length);
+    }
   if (!priv->use_es && GDK_DISPLAY_DEBUG_CHECK (display, GL_TEXTURE_RECT))
     priv->use_texture_rectangle = TRUE;
   else if (has_npot)