From 0f9bc229b4bebb0030af94b847b0acabf42e865a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Janiszewski?= <janisozaur@gmail.com>
Date: Sun, 1 Nov 2015 23:33:02 +0100
Subject: [PATCH] Fixes to safe_strncpy

* don't touch memory at all if size passed is 0
* use original address instead of now-changed `destination`
* fix one of the calls having improper size passed
---
 src/interface/console.c | 2 +-
 src/util/util.c         | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/interface/console.c b/src/interface/console.c
index a880cda82d..f9cb170361 100644
--- a/src/interface/console.c
+++ b/src/interface/console.c
@@ -188,7 +188,7 @@ void console_draw(rct_drawpixelinfo *dpi)
 		int lineLength = min(sizeof(lineBuffer) - (size_t)utf8_get_codepoint_length(FORMAT_GREEN), (size_t)(nextLine - ch));
 		lineCh = lineBuffer;
 		lineCh = utf8_write_codepoint(lineCh, FORMAT_GREEN);
-		safe_strncpy(lineCh, ch, lineLength);
+		safe_strncpy(lineCh, ch, CONSOLE_BUFFER_SIZE);
 		lineCh[lineLength] = 0;
 
 		gfx_draw_string(dpi, lineBuffer, 255, x, y);
diff --git a/src/util/util.c b/src/util/util.c
index 6138e13e39..923c08fa29 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -183,6 +183,10 @@ int strcicmp(char const *a, char const *b)
 
 char *safe_strncpy(char * destination, const char * source, size_t size)
 {
+	if (size == 0)
+	{
+		return destination;
+	}
 	char *result = destination;
 	bool terminated = false;
 	for (size_t i = 0; i < size; i++)
@@ -198,7 +202,7 @@ char *safe_strncpy(char * destination, const char * source, size_t size)
 	}
 	if (!terminated)
 	{
-		destination[size - 1] = '\0';
+		result[size - 1] = '\0';
 		log_warning("Truncating string %s to %d bytes.", destination, size);
 	}
 	return result;