Converting from an integer to HWND (which is a pointer) requires
an explicit cast, otherwise Clang errors out like this:
src/libavdevice/gdigrab.c:280:14: error: incompatible integer to pointer conversion assigning to 'HWND' (aka 'struct HWND__ *') from 'long' [-Wint-conversion]
280 | hwnd = strtol(name, &p, 0);
| ^ ~~~~~~~~~~~~~~~~~~~
(With GCC and MSVC, this was a mere warning, but with recent Clang,
this is an error.)
After adding a cast, all compilers also warn something like this:
src/libavdevice/gdigrab.c:280:16: warning: cast to 'HWND' (aka 'struct HWND__ *') from smaller integer type 'long' [-Wint-to-pointer-cast]
280 | hwnd = (HWND) strtol(name, &p, 0);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
On Windows, long types are 32 bit, so to get a usable pointer, we
need to use long long. And interpret it as unsigned long long
while at it - i.e. using strtoull.
Finally, right above it, the code triggered the following warning:
src/libavdevice/gdigrab.c:278:15: warning: mixing declarations and code is incompatible with standards before C99 [-Wdeclaration-after-statement]
278 | char *p;
| ^
Signed-off-by: Martin Storsjö <martin@martin.st>