Re: [PATCH] user.c (save_form_data_to_file): paranoid error handling

On Tue, 27 Feb 2007 13:35:37 +0300
Alexey Tourbin <[email protected]> wrote:

> This is basically to fix gcc warning:
> user.c: In function 'save_form_data_to_file':
> user.c:243: warning: ignoring return value of 'fwrite', declared with attribute warn_unused_result
> 
> Now fwrite() return value must be checked.  But I also noticed that
> temporary file is not being freed on error conditions.  And since stdio
> is buffered, fclose() return value must be checked, too.
> 
> After a few --amend's I noticed the routine does not look quite the same
> anymore.
> ---
>  src/protocol/user.c |   39 +++++++++++++++++++++++++--------------
>  1 files changed, 25 insertions(+), 14 deletions(-)
> 
> diff --git a/src/protocol/user.c b/src/protocol/user.c
> index e00cf72..fe45968 100644
> --- a/src/protocol/user.c
> +++ b/src/protocol/user.c
> @@ -217,32 +217,43 @@ static unsigned char *
>  save_form_data_to_file(struct uri *uri)
>  {
>  	unsigned char *filename = get_tempdir_filename("elinks-XXXXXX");
> -	int formfd;
> -	FILE *formfile;
> +	int fd;
> +	FILE *fp;
> +	unsigned char *formdata;
> +	size_t len, nmemb;
>  
>  	if (!filename) return NULL;
>  
> -	formfd = safe_mkstemp(filename);
> -	if (formfd < 0) {
> +	fd = safe_mkstemp(filename);
> +	if (fd < 0) {
>  		mem_free(filename);
>  		return NULL;
>  	}
>  
> -	formfile = fdopen(formfd, "w");
> -	if (!formfile) {
> +	if (!uri->post) return filename;
> +
> +	/* Jump the content type */
> +	formdata = strchr(uri->post, '\n');
> +	formdata = formdata ? formdata + 1 : uri->post;
> +	len = strlen(formdata);
> +	if (len == 0) return filename;
> +
> +	fp = fdopen(fd, "w");
> +	if (!fp) {
> +error:		unlink(filename);
>  		mem_free(filename);
> -		close(formfd);
> +		close(fd);
>  		return NULL;
>  	}
>  
> -	if (uri->post) {
> -		/* Jump the content type */
> -		unsigned char *formdata = strchr(uri->post, '\n');
> -
> -		formdata = formdata ? formdata + 1 : uri->post;
> -		fwrite(formdata, strlen(formdata), 1, formfile);
> +	nmemb = fwrite(formdata, len, 1, fp);
> +	if (nmemb != 1) {
> +		fclose(fp);
> +		goto error;
>  	}
> -	fclose(formfile);
> +
> +	if (fclose(fp) != 0)
> +		goto error;
>  
>  	return filename;
>  }
> -- 
> 1.5.0.1.GIT
> 

Thanks, committed in master branch.

Kind regards,

--

Zas