1 files changed, 17 insertions, 0 deletions
diff --git a/mesalib/src/mesa/main/lines.c b/mesalib/src/mesa/main/lines.c
index 79bf5679d..e400b3913 100644
--- a/mesalib/src/mesa/main/lines.c
+++ b/mesalib/src/mesa/main/lines.c
@@ -51,6 +51,23 @@ _mesa_LineWidth( GLfloat width )
       return;
    }
 
+   /* Page 407 (page 423 of the PDF) of the OpenGL 3.0 spec says (in the list
+    * of deprecated functionality):
+    *
+    *     "Wide lines and line stipple - LineWidth is not deprecated, but
+    *     values greater than 1.0 will generate an INVALID_VALUE error;"
+    *
+    * This is one of the very few cases where functionality was deprecated but
+    * *NOT* removed in a later spec.  Therefore, we only disallow this in a
+    * forward compatible context.
+    */
+   if (ctx->API == API_OPENGL_CORE
+       && ((ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
+           != 0)) {
+      _mesa_error( ctx, GL_INVALID_VALUE, "glLineWidth" );
+      return;
+   }
+
    if (ctx->Line.Width == width)
       return;