3 files changed, 23 insertions, 3 deletions
diff --git a/compat/mingw.c b/compat/mingw.c
index f90a114b02..9a8e336582 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -140,6 +140,23 @@ int mingw_open (const char *filename, int oflags, ...)
 	return fd;
 }
 
+#undef write
+ssize_t mingw_write(int fd, const void *buf, size_t count)
+{
+	/*
+	 * While write() calls to a file on a local disk are translated
+	 * into WriteFile() calls with a maximum size of 64KB on Windows
+	 * XP and 256KB on Vista, no such cap is placed on writes to
+	 * files over the network on Windows XP.  Unfortunately, there
+	 * seems to be a limit of 32MB-28KB on X64 and 64MB-32KB on x86;
+	 * bigger writes fail on Windows XP.
+	 * So we cap to a nice 31MB here to avoid write failures over
+	 * the net without changing the number of WriteFile() calls in
+	 * the local case.
+	 */
+	return write(fd, buf, min(count, 31 * 1024 * 1024));
+}
+
 #undef fopen
 FILE *mingw_fopen (const char *filename, const char *otype)
 {
diff --git a/compat/mingw.h b/compat/mingw.h
index 7c2ab64cb4..0e3e743041 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -170,6 +170,9 @@ int link(const char *oldpath, const char *newpath);
 int mingw_open (const char *filename, int oflags, ...);
 #define open mingw_open
 
+ssize_t mingw_write(int fd, const void *buf, size_t count);
+#define write mingw_write
+
 FILE *mingw_fopen (const char *filename, const char *otype);
 #define fopen mingw_fopen
 
diff --git a/compat/win32mmap.c b/compat/win32mmap.c
index 1c5a14922f..b58aa69fa0 100644
--- a/compat/win32mmap.c
+++ b/compat/win32mmap.c
@@ -4,19 +4,19 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of
 {
 	HANDLE hmap;
 	void *temp;
-	size_t len;
+	off_t len;
 	struct stat st;
 	uint64_t o = offset;
 	uint32_t l = o & 0xFFFFFFFF;
 	uint32_t h = (o >> 32) & 0xFFFFFFFF;
 
 	if (!fstat(fd, &st))
-		len = xsize_t(st.st_size);
+		len = st.st_size;
 	else
 		die("mmap: could not determine filesize");
 
 	if ((length + offset) > len)
-		length = len - offset;
+		length = xsize_t(len - offset);
 
 	if (!(flags & MAP_PRIVATE))
 		die("Invalid usage of mmap when built with USE_WIN32_MMAP");