path: add git__percent_decode()

1 files changed, 35 insertions, 0 deletions

diff --git a/src/path.c b/src/path.c
index e4b49f35d..bd62a3e4d 100644
--- a/src/path.c
+++ b/src/path.c
@@ -237,3 +237,38 @@ void git_path_string_to_dir(char* path, size_t size)
 	}
 }
 
+int git__percent_decode(git_buf *decoded_out, const char *input)
+{
+	int len, hi, lo, i, error = GIT_SUCCESS;
+	assert(decoded_out && input);
+
+	len = strlen(input);
+	git_buf_clear(decoded_out);
+
+	for(i = 0; i < len; i++)
+	{
+		char c = input[i];
+
+		if (c != '%')
+			goto append;
+
+		if (i >= len - 2)
+			goto append;
+
+		hi = git__fromhex(input[i + 1]);
+		lo = git__fromhex(input[i + 2]);
+
+		if (hi < 0 || lo < 0)
+			goto append;
+
+		c = (char)(hi << 4 | lo);
+		i += 2;
+
+append:
+		error = git_buf_putc(decoded_out, c);
+		if (error < GIT_SUCCESS)
+			return git__rethrow(error, "Failed to percent decode '%s'.", input);
+	}
+
+	return error;
+}