From c1ef7afcac21d7bc9536ca2dc309dd9dd57169d2 Mon Sep 17 00:00:00 2001
From: Abdelrahman Said <said.abdelrahman89@gmail.com>
Date: Sun, 9 Jul 2023 21:21:50 +0100
Subject: [PATCH] Added more checks for NULL pointers

---
 src/dstring.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/dstring.c b/src/dstring.c
index f6dd3d7..47e6eec 100644
--- a/src/dstring.c
+++ b/src/dstring.c
@@ -29,6 +29,10 @@ dstr_t *dstr_with_capacity(u64 capacity) {
 }
 
 dstr_t *dstr_from_string(const char *str) {
+  if (!str) {
+    return NULL;
+  }
+
   u64 length = strlen(str);
 
   u64 capacity = length * CAPACITY_SCALAR;
@@ -46,7 +50,7 @@ dstr_t *dstr_from_string(const char *str) {
 }
 
 void dstr_update(dstr_t **dst, const char *src) {
-  if (!(*dst)) {
+  if (!dst || !(*dst)) {
     return;
   }
 
@@ -78,7 +82,7 @@ void dstr_update(dstr_t **dst, const char *src) {
 }
 
 void dstr_free(dstr_t **str) {
-  if (!(*str)) {
+  if (!str || !(*str)) {
     return;
   }
 
@@ -87,7 +91,7 @@ void dstr_free(dstr_t **str) {
 }
 
 void dstr_concat(dstr_t **dst, const char *src) {
-  if (!(*dst)) {
+  if (!dst || !(*dst)) {
     return;
   }
 
@@ -109,7 +113,7 @@ void dstr_concat(dstr_t **dst, const char *src) {
 }
 
 void dstr_append(dstr_t **dst, char c) {
-  if (!(*dst)) {
+  if (!dst || !(*dst)) {
     return;
   }
 
@@ -125,6 +129,10 @@ void dstr_append(dstr_t **dst, char c) {
 }
 
 void dstr_resize(dstr_t **str) {
+  if (!str || !(*str)) {
+    return;
+  }
+
   u64 capacity = (*str)->size;
 
   dstr_t *tmp = (dstr_t *)realloc(*str, sizeof(dstr_t) + capacity + 1);
@@ -169,7 +177,7 @@ i64 dstr_find(const dstr_t *str, const char *substr) {
   char buf[substr_length + 1];
   memset(buf, 0, substr_length + 1);
 
-  for (i64 i = 0; i < str->size; ++i) {
+  for (u64 i = 0; i < str->size; ++i) {
     if (i + substr_length >= str->size) {
       break;
     }