posix: remove `p_fallocate` abstraction

By now, we have repeatedly failed to provide a nice
cross-platform implementation of `p_fallocate`. Recent tries to
do that escalated quite fast to a set of different CMake checks,
implementations, fallbacks, etc., which started to look real
awkward to maintain. In fact, `p_fallocate` had only been
introduced in commit 4e3949b73 (tests: test that largefiles can
be read through the tree API, 2019-01-30) to support a test with
large files, but given the maintenance costs it just seems not to
be worht it.

As we have removed the sole user of `p_fallocate` in the previous
commit, let's drop it altogether.

1 files changed, 0 insertions, 52 deletions

diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index c082dbacd..91e164348 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -525,58 +525,6 @@ int p_creat(const char *path, mode_t mode)
 	return p_open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
 }
 
-int p_fallocate(int fd, off_t offset, off_t len)
-{
-	HANDLE fh = (HANDLE)_get_osfhandle(fd);
-	LARGE_INTEGER zero, position, oldsize, newsize;
-	size_t size;
-
-	if (fh == INVALID_HANDLE_VALUE) {
-		errno = EBADF;
-		return -1;
-	}
-
-	if (offset < 0 || len <= 0) {
-		errno = EINVAL;
-		return -1;
-	}
-
-	if (git__add_sizet_overflow(&size, offset, len)) {
-		errno = EINVAL;
-		return -1;
-	}
-
-	zero.u.LowPart = 0;
-	zero.u.HighPart = 0;
-
-	newsize.u.LowPart = (size & 0xffffffff);
-
-#if (SIZE_MAX > UINT32_MAX)
-	newsize.u.HighPart = size >> 32;
-#else
-	newsize.u.HighPart = 0;
-#endif
-
-	if (!GetFileSizeEx(fh, &oldsize)) {
-		set_errno();
-		return -1;
-	}
-
-	/* POSIX emulation: attempting to shrink the file is ignored */
-	if (oldsize.QuadPart >= newsize.QuadPart)
-		return 0;
-
-	if (!SetFilePointerEx(fh, zero, &position, FILE_CURRENT) ||
-	    !SetFilePointerEx(fh, newsize, NULL, FILE_BEGIN) ||
-	    !SetEndOfFile(fh) ||
-	    !SetFilePointerEx(fh, position, 0, FILE_BEGIN)) {
-		set_errno();
-		return -1;
-	}
-
-	return 0;
-}
-
 int p_utimes(const char *path, const struct p_timeval times[2])
 {
 	git_win32_path wpath;