Merge pull request #2932 from jeffhostetler/jeffhostetler/big_clone_crash

Fix crash in git_clone on extremely large repos

2 files changed, 21 insertions, 5 deletions

diff --git a/src/win32/posix.h b/src/win32/posix.h
index 104966edc..9ac78430b 100644
--- a/src/win32/posix.h
+++ b/src/win32/posix.h
@@ -41,7 +41,7 @@ extern int p_chdir(const char* path);
 extern int p_chmod(const char* path, mode_t mode);
 extern int p_rmdir(const char* path);
 extern int p_access(const char* path, mode_t mode);
-extern int p_ftruncate(int fd, long size);
+extern int p_ftruncate(int fd, git_off_t size);
 
 /* p_lstat is almost but not quite POSIX correct.  Specifically, the use of
  * ENOTDIR is wrong, in that it does not mean precisely that a non-directory
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index 6e005c1cd..b8b4f43f8 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -42,12 +42,28 @@
 /* GetFinalPathNameByHandleW signature */
 typedef DWORD(WINAPI *PFGetFinalPathNameByHandleW)(HANDLE, LPWSTR, DWORD, DWORD);
 
-int p_ftruncate(int fd, long size)
+/**
+ * Truncate or extend file.
+ *
+ * We now take a "git_off_t" rather than "long" because
+ * files may be longer than 2Gb.
+ */
+int p_ftruncate(int fd, git_off_t size)
 {
-#if defined(_MSC_VER) && _MSC_VER >= 1500
-	return _chsize_s(fd, size);
+	if (size < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+#if !defined(__MINGW32__)
+	return ((_chsize_s(fd, size) == 0) ? 0 : -1);
 #else
-	return _chsize(fd, size);
+	/* TODO MINGW32 Find a replacement for _chsize() that handles big files. */
+	if (size > INT32_MAX) {
+		errno = EFBIG;
+		return -1;
+	}
+	return _chsize(fd, (long)size);
 #endif
 }