[FFmpeg-devel] (no subject)

[cyfdel at hotmail.com]

hat the patch does:
        fix gdigrab capture a window with hwnd shows "Invalid window
        handle x, must be a vlid integer", althought a valid integer is
        input

why:
        line 284 of libavdevice/gdigrab.c, one of the condition leads to
        check failed is p[0]='\0'. if a integer only string is process,
        the p[0] after strtoull process will be null which equal to
        '\0', otherwise, a non-integer string will make p[0] not null to
        pass the check

how:
        change p[0]=='\0' to p[0]!='\0' will works. no any side effect

reproduce and verify:
        a simple command: ffmpeg -f gdigrab -i hwnd=12345
        * althought a workaround command will work currently:
        *       ffmpeg -f gdigrab -i hwnd=12345x. (x could be any char)