From b5847b2ab13355e3ed264be1a812facb4fd46fbe Mon Sep 17 00:00:00 2001
From: Kreeblah <kreeblah@gmail.com>
Date: Sun, 31 Jan 2021 00:16:16 -0800
Subject: [PATCH] Additional checks to reduce the possibility of user error
 with snes_clk.txt clock offset file.

---
 Cart_Reader/snes_clk.cpp | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/Cart_Reader/snes_clk.cpp b/Cart_Reader/snes_clk.cpp
index 8947f3f..1ba096a 100644
--- a/Cart_Reader/snes_clk.cpp
+++ b/Cart_Reader/snes_clk.cpp
@@ -6,20 +6,38 @@ int32_t readClockOffset() {
 	unsigned char* clock_buf;
 	int16_t i;
 	int32_t clock_offset;
+
 	if(!clock_file.open("/snes_clk.txt", FILE_READ)) {
 		return INT32_MIN;
 	}
 
-	clock_buf = malloc(16 * sizeof(char));
-	i = clock_file.read(clock_buf, 16);
+	clock_buf = malloc(12 * sizeof(char));
+	i = clock_file.read(clock_buf, 11);
 	clock_file.close();
 	if(i == -1) {
 		free(clock_buf);
 		return INT32_MIN;
-	} else if(i < 16) {
+	} else if((i == 11) && (clock_buf[0] != '-')) {
+		free(clock_buf);
+		return INT32_MIN;
+	} else {
 		clock_buf[i] = 0;
 	}
 
+	for(i = 0; i < 12; i++) {
+		if(clock_buf[i] != '-' && clock_buf[i] < '0' && clock_buf[i] > '9') {
+			if(i == 0) {
+				free(clock_buf);
+				return INT32_MIN;
+			} else if((i == 1) && (clock_buf[0] == '-')) {
+				free(clock_buf);
+				return INT32_MIN;
+			} else {
+				clock_buf[i] = 0;
+			}
+		}
+	}
+
 	clock_offset = (int32_t)atoi(clock_buf);
 	free(clock_buf);