[PATCH V2 2/3] load_image: always print a message on failure if filename is not empty

[Pekka Paalanen]

On Tue, 19 Aug 2014 18:13:10 -0700
Bill Spitzak <spitzak at gmail.com> wrote:

> It was rather inconsistent before. This may help users figure out why
> backgrounds and icons don't show up. A better api where the error can
> be queried might be nice, but this seems sufficient for current Weston use.
> ---
>  shared/image-loader.c |   14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/shared/image-loader.c b/shared/image-loader.c
> index 35dadd3..0d04b03 100644
> --- a/shared/image-loader.c
> +++ b/shared/image-loader.c
> @@ -23,6 +23,7 @@
>  
>  #include "config.h"
>  
> +#include <errno.h>
>  #include <stdlib.h>
>  #include <stdio.h>
>  #include <string.h>
> @@ -374,12 +375,18 @@ load_image(const char *filename)
>  	FILE *fp;
>  	unsigned int i;
>  
> +	if (!filename || !*filename)
> +		return NULL;
> +
>  	fp = fopen(filename, "rb");
> -	if (fp == NULL)
> +	if (!fp) {
> +		fprintf(stderr, "%s: %s\n", filename, strerror(errno));
>  		return NULL;
> +	}
>  
>  	if (fread(header, sizeof header, 1, fp) != 1) {
>  		fclose(fp);
> +		fprintf(stderr, "%s: unable to read file header\n", filename);
>  		return NULL;
>  	}
>  
> @@ -395,10 +402,13 @@ load_image(const char *filename)
>  	fclose(fp);
>  
>  	if (i == ARRAY_LENGTH(loaders)) {
> -		fprintf(stderr, "unrecognized file header for %s: "
> +		fprintf(stderr, "%s: unrecognized file header "
>  			"0x%02x 0x%02x 0x%02x 0x%02x\n",
>  			filename, header[0], header[1], header[2], header[3]);
>  		image = NULL;
> +	} else if (!image) {
> +		/* load probably printed something, but just in case */
> + 		fprintf(stderr, "%s: error reading image\n", filename);
>  	}
>  
>  	return image;

Yes, at least there is something always printed now. Compositor-x11.c
is using load_image() directly to load the icon for the X11 window.
When that fails, we should really use weston_log() for the error
message, but I see that is a bit labourious to implement without
losing the exact header error message, so as you wrote, this is
sufficient for now.

I removed one stray space.

Pushed.


Thanks,
pq