1 files changed, 144 insertions, 0 deletions
diff --git a/src/util/win32/utf-conv.c b/src/util/win32/utf-conv.c
new file mode 100644
index 0000000..ad35c0c
--- /dev/null
+++ b/src/util/win32/utf-conv.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "utf-conv.h"
+
+GIT_INLINE(void) git__set_errno(void)
+{
+	if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		errno = ENAMETOOLONG;
+	else
+		errno = EINVAL;
+}
+
+int git_utf8_to_16(wchar_t *dest, size_t dest_size, const char *src)
+{
+	/* Length of -1 indicates NULL termination of the input string. */
+	return git_utf8_to_16_with_len(dest, dest_size, src, -1);
+}
+
+int git_utf8_to_16_with_len(
+	wchar_t *dest,
+	size_t _dest_size,
+	const char *src,
+	int src_len)
+{
+	int dest_size = (int)min(_dest_size, INT_MAX);
+	int len;
+
+	/*
+	 * Subtract 1 from the result to turn 0 into -1 (an error code) and
+	 * to not count the NULL terminator as part of the string's length.
+	 * MultiByteToWideChar never returns int's minvalue, so underflow
+	 * is not possible.
+	 */
+	len = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS,
+		src, src_len, dest, dest_size) - 1;
+
+	if (len < 0)
+		git__set_errno();
+
+	return len;
+}
+
+int git_utf8_from_16(char *dest, size_t dest_size, const wchar_t *src)
+{
+	/* Length of -1 indicates NULL termination of the input string. */
+	return git_utf8_from_16_with_len(dest, dest_size, src, -1);
+}
+
+int git_utf8_from_16_with_len(
+	char *dest,
+	size_t _dest_size,
+	const wchar_t *src,
+	int src_len)
+{
+	int dest_size = (int)min(_dest_size, INT_MAX);
+	int len;
+
+	/*
+	 * Subtract 1 from the result to turn 0 into -1 (an error code) and
+	 * to not count the NULL terminator as part of the string's length.
+	 * WideCharToMultiByte never returns int's minvalue, so underflow
+	 * is not possible.
+	 */
+	len = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS,
+		src, src_len, dest, dest_size, NULL, NULL) - 1;
+
+	if (len < 0)
+		git__set_errno();
+
+	return len;
+}
+
+int git_utf8_to_16_alloc(wchar_t **dest, const char *src)
+{
+	/* Length of -1 indicates NULL termination of the input string. */
+	return git_utf8_to_16_alloc_with_len(dest, src, -1);
+}
+
+int git_utf8_to_16_alloc_with_len(wchar_t **dest, const char *src, int src_len)
+{
+	int utf16_size;
+
+	*dest = NULL;
+
+	utf16_size = MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS,
+		src, src_len, NULL, 0);
+
+	if (!utf16_size) {
+		git__set_errno();
+		return -1;
+	}
+
+	*dest = git__mallocarray(utf16_size, sizeof(wchar_t));
+	GIT_ERROR_CHECK_ALLOC(*dest);
+
+	utf16_size = git_utf8_to_16_with_len(*dest, (size_t)utf16_size,
+		src, src_len);
+
+	if (utf16_size < 0) {
+		git__free(*dest);
+		*dest = NULL;
+	}
+
+	return utf16_size;
+}
+
+int git_utf8_from_16_alloc(char **dest, const wchar_t *src)
+{
+	/* Length of -1 indicates NULL termination of the input string. */
+	return git_utf8_from_16_alloc_with_len(dest, src, -1);
+}
+
+int git_utf8_from_16_alloc_with_len(char **dest, const wchar_t *src, int src_len)
+{
+	int utf8_size;
+
+	*dest = NULL;
+
+	utf8_size = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS,
+		src, src_len, NULL, 0, NULL, NULL);
+
+	if (!utf8_size) {
+		git__set_errno();
+		return -1;
+	}
+
+	*dest = git__malloc(utf8_size);
+	GIT_ERROR_CHECK_ALLOC(*dest);
+
+	utf8_size = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS,
+		src, src_len, *dest, utf8_size, NULL, NULL);
+
+	if (utf8_size < 0) {
+		git__free(*dest);
+		*dest = NULL;
+	}
+
+	return utf8_size;
+}