From 63184052be386dc2c683bb225aa08bcf92394f61 Mon Sep 17 00:00:00 2001
From: Hielke Morsink <hielke.morsink@gmail.com>
Date: Sun, 29 Nov 2015 16:00:05 +0100
Subject: [PATCH] minor optimizations and added comments to some util functions

---
 src/util/util.c | 60 +++++++++++++++++++------------------------------
 1 file changed, 23 insertions(+), 37 deletions(-)

diff --git a/src/util/util.c b/src/util/util.c
index 890423e0fd..fabf55f925 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -55,62 +55,48 @@ bool filename_valid_characters(const utf8 *filename)
 
 const char *path_get_filename(const utf8 *path)
 {
-	const char *result, *ch;
+	// Find last slash or backslash in the path
+	char *filename = strrchr(path, '/');
+	if (filename == NULL)
+		filename = strrchr(path, '\\');
 
-	result = path;
-	for (ch = path; *ch != 0; ch++) {
-		if (*ch == '/' || *ch == '\\') {
-			if (*(ch + 1) != 0)
-				result = ch + 1;
-		}
-	}
+	assert(filename != NULL);
 
-	return result;
+	// Increase pointer by one, to get rid of the slashes
+	filename++;
+
+	return filename;
 }
 
 const char *path_get_extension(const utf8 *path)
 {
-	const char *extension = NULL;
-	const char *ch = path;
-	while (*ch != 0) {
-		if (*ch == '.')
-			extension = ch;
+	// Try to find the most-right dot in the path
+	char *extension = strrchr(path, '.');
 
-		ch++;
-	}
+	// When NULL was returned, return a pointer to the null-terminator
 	if (extension == NULL)
-		extension = ch;
+		extension = strrchr(path, '\0');
+
 	return extension;
 }
 
 void path_set_extension(utf8 *path, const utf8 *newExtension)
 {
-	char *extension = NULL;
-	char *ch = path;
-	while (*ch != 0) {
-		if (*ch == '.')
-			extension = ch;
-
-		ch++;
-	}
-	if (extension == NULL)
-		extension = ch;
-
+	// Append a dot to the filename if the new extension doesn't start with it
+	char *endOfString = strrchr(path, '\0');
 	if (newExtension[0] != '.')
-		*extension++ = '.';
+		*endOfString++ = '.';
 
-	strcpy(extension, newExtension);
+	// Append the extension to the path
+	// No existing extensions should be removed ("ride.TD6" -> "ride.TD6.TD6")
+	safe_strncpy(endOfString, newExtension, MAX_PATH - (endOfString - path) - 1);
 }
 
 void path_remove_extension(utf8 *path)
 {
-	char *ch = path + strlen(path);
-	for (--ch; ch >= path; --ch) {
-		if (*ch == '.') {
-			*ch = '\0';
-			break;
-		}
-	}
+	// Find last dot in filename, and replace it with a null-terminator
+	char *lastDot = strrchr(path, '.');
+	if (*lastDot) *lastDot = '\0';
 }
 
 bool readentirefile(const utf8 *path, void **outBuffer, int *outLength)