[Spice-devel] [PATCH spice-common] canvas: Prevent some error compiling spice-gtk

[Frediano Ziglio]

ping

Currently master is failing to compiler, see
https://gitlab.com/spice/spice-gtk/-/jobs

This is supposed to be the patch in spice-gtk that take the spice-common changes:
https://lists.freedesktop.org/archives/spice-devel/2018-January/041472.html

Frediano

> 
> Due to different warning setting some GCC reports:
> 
> In file included from ../spice-common/common/sw_canvas.c:27:0,
>                  from client_sw_canvas.c:20:
> ../spice-common/common/canvas_base.c: In function ‘canvas_get_lz’:
> ../spice-common/common/canvas_base.c:768:13: error: ‘palette’ may be used
> uninitialized in this function [-Werror=maybe-uninitialized]
>              free(palette);
>              ^~~~~~~~~~~~~
> ../spice-common/common/canvas_base.c:764:9: error: variable ‘free_palette’
> might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]
>      int free_palette = FALSE;
>          ^~~~~~~~~~~~
> cc1: all warnings being treated as errors
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  common/canvas_base.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/common/canvas_base.c b/common/canvas_base.c
> index 42f0eea..90d1d38 100644
> --- a/common/canvas_base.c
> +++ b/common/canvas_base.c
> @@ -754,14 +754,14 @@ static pixman_image_t *canvas_get_lz(CanvasBase
> *canvas, SpiceImage *image,
>      uint8_t    *decomp_buf = NULL;
>      pixman_format_code_t pixman_format;
>      LzImageType type, as_type;
> -    SpicePalette *palette;
> +    SpicePalette *palette = NULL;
>      int n_comp_pixels;
>      int width;
>      int height;
>      int top_down;
>      int stride_encoded;
>      int stride;
> -    int free_palette = FALSE;
> +    volatile int free_palette = FALSE;
>  
>      if (setjmp(lz_data->jmp_env)) {
>          if (free_palette)  {
> @@ -781,7 +781,9 @@ static pixman_image_t *canvas_get_lz(CanvasBase *canvas,
> SpiceImage *image,
>          spice_return_val_if_fail(image->u.lz_plt.data->num_chunks == 1,
>          NULL); /* TODO: Handle chunks */
>          comp_buf = image->u.lz_plt.data->chunk[0].data;
>          comp_size = image->u.lz_plt.data->chunk[0].len;
> -        palette = canvas_get_localized_palette(canvas,
> image->u.lz_plt.palette, image->u.lz_plt.palette_id, image->u.lz_plt.flags,
> &free_palette);
> +        palette = canvas_get_localized_palette(canvas,
> image->u.lz_plt.palette,
> +                                               image->u.lz_plt.palette_id,
> image->u.lz_plt.flags,
> +                                               (int*) &free_palette);
>      } else {
>          spice_warn_if_reached();
>          return NULL;