[Mesa-dev] [PATCH] draw: don't crash if GS doesn't emit anything

[Zack Rusin]

Technically it's legal for geometry shader to not emit any
vertices. It's silly, but perfectly legal, so lets make draw
stop crashing if it happens.

Signed-off-by: Zack Rusin <zackr at vmware.com>
---
 src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c     |    9 +++++++++
 .../auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c        |    9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
index 7b871c2..8d66c88 100644
--- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
+++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline.c
@@ -299,6 +299,15 @@ static void fetch_pipeline_generic( struct draw_pt_middle_end *middle,
          }
       }
    }
+   if (prim_info->count == 0) {
+      debug_printf("GS/IA didn't emit any vertices!\n");
+      
+      FREE(vert_info->verts);
+      if (free_prim_info) {
+         FREE(prim_info->primitive_lengths);
+      }
+      return;
+   }
 
 
    /* Stream output needs to be done before clipping.
diff --git a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
index 0873e34..48fb616 100644
--- a/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_pt_fetch_shade_pipeline_llvm.c
@@ -397,6 +397,15 @@ llvm_pipeline_generic( struct draw_pt_middle_end *middle,
          }
       }
    }
+   if (prim_info->count == 0) {
+      debug_printf("GS/IA didn't emit any vertices!\n");
+      
+      FREE(vert_info->verts);
+      if (free_prim_info) {
+         FREE(prim_info->primitive_lengths);
+      }
+      return;
+   }
 
    /* stream output needs to be done before clipping */
    draw_pt_so_emit( fpme->so_emit, vert_info, prim_info );
-- 
1.7.10.4