renderer: cleanup context create errors and context destroy

src/virglrenderer.c

@@ -62,8 +62,7 @@ void virgl_renderer_fill_caps(uint32_t set, uint32_t version,
 
 int virgl_renderer_context_create(uint32_t handle, uint32_t nlen, const char *name)
 {
-   vrend_renderer_context_create(handle, nlen, name);
-   return 0;
+   return vrend_renderer_context_create(handle, nlen, name);
 }
 
 void virgl_renderer_context_destroy(uint32_t handle)

src/vrend_decode.c

@@ -985,25 +985,29 @@ void vrend_renderer_context_create_internal(uint32_t handle, uint32_t nlen,
    dec_ctx[handle] = dctx;
 }
 
-void vrend_renderer_context_create(uint32_t handle, uint32_t nlen, const char *debug_name)
+int vrend_renderer_context_create(uint32_t handle, uint32_t nlen, const char *debug_name)
 {
    if (handle > VREND_MAX_CTX)
-      return;
+      return EINVAL;
    /* context 0 is always available with no guarantees */
    if (handle == 0)
-      return;
+      return EINVAL;
 
    vrend_renderer_context_create_internal(handle, nlen, debug_name);
+   return 0;
 }
 
 void vrend_renderer_context_destroy(uint32_t handle)
 {
    struct vrend_decode_ctx *ctx;
    bool ret;
+
    if (handle > VREND_MAX_CTX)
       return;
 
    ctx = dec_ctx[handle];
+   if (!ctx)
+     return;
    dec_ctx[handle] = NULL;
    ret = vrend_destroy_context(ctx->grctx);
    free(ctx);

src/vrend_renderer.h

@@ -124,7 +124,7 @@ void vrend_flush(struct vrend_context *ctx);
 void vrend_flush_frontbuffer(uint32_t res_handle);
 struct vrend_context *vrend_create_context(int id, uint32_t nlen, const char *debug_name);
 bool vrend_destroy_context(struct vrend_context *ctx);
-void vrend_renderer_context_create(uint32_t handle, uint32_t nlen, const char *name);
+int vrend_renderer_context_create(uint32_t handle, uint32_t nlen, const char *name);
 void vrend_renderer_context_create_internal(uint32_t handle, uint32_t nlen, const char *name);
 void vrend_renderer_context_destroy(uint32_t handle);