[PATCH weston] backends: don't run off the end of strings

[Derek Foreman]

Fair enough.  The patch is useless. :)

Thanks

On 23/10/14 01:43 PM, Bill Spitzak wrote:
> That won't run off the end of a zero or one-length string.
> 
> If strlen() works then there is a nul byte there. The first test against
> 'W' will fail because 0 != 'W', and the second test will not be run.
> 
> On 10/23/2014 10:21 AM, Derek Foreman wrote:
>> Strings from the config parser can be of length 0, so we should check
>> that before checking the string's bytes.
>>
>> The x11 backend's usage is technically safe since the null terminator
>> is present, but I've changed it too in case someone's looking at it as
>> a reference for new code.
>> ---
>>   src/compositor-wayland.c | 2 +-
>>   src/compositor-x11.c     | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/compositor-wayland.c b/src/compositor-wayland.c
>> index bf71a76..e107002 100644
>> --- a/src/compositor-wayland.c
>> +++ b/src/compositor-wayland.c
>> @@ -2108,7 +2108,7 @@ backend_init(struct wl_display *display, int
>> *argc, char *argv[],
>>           if (name == NULL)
>>               continue;
>>
>> -        if (name[0] != 'W' || name[1] != 'L') {
>> +        if (strlen(name) < 2 || name[0] != 'W' || name[1] != 'L') {
>>               free(name);
>>               continue;
>>           }
>> diff --git a/src/compositor-x11.c b/src/compositor-x11.c
>> index 1baee29..ae237c8 100644
>> --- a/src/compositor-x11.c
>> +++ b/src/compositor-x11.c
>> @@ -1550,7 +1550,7 @@ x11_compositor_create(struct wl_display *display,
>>           if (strcmp(section_name, "output") != 0)
>>               continue;
>>           weston_config_section_get_string(section, "name", &name, NULL);
>> -        if (name == NULL || name[0] != 'X') {
>> +        if (name == NULL || strlen(name) < 1 || name[0] != 'X') {
>>               free(name);
>>               continue;
>>           }
>>
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