win32mmap: set errno appropriately

It is not really helpful when a `git fetch` fails with the message: fatal: mmap failed: No error In the particular instance encountered by a colleague of yours truly, the Win32 error code was ERROR_COMMITMENT_LIMIT which means that the page file is not big enough. Let's make the message fatal: mmap failed: File too large instead, which is only marginally better, but which can be associated with the appropriate work-around: setting `core.packedGitWindowSize` to a relatively small value. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Apr 22, 2016 at 16:31 UTC 6a730e10a76d1e03a9554292419201534c1521f1
1 file changed +8 -2
compat/win32mmap.c
+8 -2
@@ -24,15 +24,21 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
24 hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL,
25 PAGE_WRITECOPY, 0, 0, NULL);
26
27 - if (!hmap)
27 + if (!hmap) {
28 + errno = EINVAL;
29 return MAP_FAILED;
30 + }
31
32 temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
33
34 if (!CloseHandle(hmap))
35 warning("unable to close file mapping handle");
36
35 - return temp ? temp : MAP_FAILED;
37 + if (temp)
38 + return temp;
39 +
40 + errno = GetLastError() == ERROR_COMMITMENT_LIMIT ? EFBIG : EINVAL;
41 + return MAP_FAILED;
42 }
43
44 int git_munmap(void *start, size_t length)