git_buf_put_w: introduce utf16->utf8 conversion

4 files changed, 77 insertions, 4 deletions

diff --git a/src/win32/buffer.c b/src/win32/buffer.c
new file mode 100644
index 000000000..74950189e
--- /dev/null
+++ b/src/win32/buffer.c
@@ -0,0 +1,55 @@
+/*
+ * 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 "common.h"
+#include "buffer.h"
+#include "../buffer.h"
+#include "utf-conv.h"
+
+GIT_INLINE(int) handle_wc_error(void)
+{
+	if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+		errno = ENAMETOOLONG;
+	else
+		errno = EINVAL;
+
+	return -1;
+}
+
+int git_buf_put_w(git_buf *buf, const wchar_t *string_w, size_t len_w)
+{
+	int utf8_len, utf8_write_len;
+	size_t new_size;
+
+	if (!len_w)
+		return 0;
+
+	assert(string_w);
+
+	/* Measure the string necessary for conversion */
+	if ((utf8_len = WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS, string_w, len_w, NULL, 0, NULL, NULL)) == 0)
+		return 0;
+
+	assert(utf8_len > 0);
+
+	GITERR_CHECK_ALLOC_ADD(&new_size, buf->size, (size_t)utf8_len);
+	GITERR_CHECK_ALLOC_ADD(&new_size, new_size, 1);
+
+	if (git_buf_grow(buf, new_size) < 0)
+		return -1;
+
+	if ((utf8_write_len = WideCharToMultiByte(
+			CP_UTF8, WC_ERR_INVALID_CHARS, string_w, len_w, &buf->ptr[buf->size], utf8_len, NULL, NULL)) == 0)
+		return handle_wc_error();
+
+	assert(utf8_write_len == utf8_len);
+
+	buf->size += utf8_write_len;
+	buf->ptr[buf->size] = '\0';
+	return 0;
+}
+
diff --git a/src/win32/buffer.h b/src/win32/buffer.h
new file mode 100644
index 000000000..62243986f
--- /dev/null
+++ b/src/win32/buffer.h
@@ -0,0 +1,18 @@
+/*
+ * 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.
+ */
+#ifndef INCLUDE_git_win32_buffer_h__
+#define INCLUDE_git_win32_buffer_h__
+
+#include "../buffer.h"
+
+/**
+ * Convert a wide character string to UTF-8 and append the results to the
+ * buffer.
+ */
+int git_buf_put_w(git_buf *buf, const wchar_t *string_w, size_t len_w);
+
+#endif
diff --git a/src/win32/utf-conv.c b/src/win32/utf-conv.c
index 0dad4eab0..f1b674ea0 100644
--- a/src/win32/utf-conv.c
+++ b/src/win32/utf-conv.c
@@ -8,10 +8,6 @@
 #include "common.h"
 #include "utf-conv.h"
 
-#ifndef WC_ERR_INVALID_CHARS
-# define WC_ERR_INVALID_CHARS	0x80
-#endif
-
 GIT_INLINE(DWORD) get_wc_flags(void)
 {
 	static char inited = 0;
diff --git a/src/win32/utf-conv.h b/src/win32/utf-conv.h
index 89cdb96da..33b95f59f 100644
--- a/src/win32/utf-conv.h
+++ b/src/win32/utf-conv.h
@@ -10,6 +10,10 @@
 #include <wchar.h>
 #include "common.h"
 
+#ifndef WC_ERR_INVALID_CHARS
+# define WC_ERR_INVALID_CHARS	0x80
+#endif
+
 /**
  * Converts a UTF-8 string to wide characters.
  *