apply suggestions from code review

Author: LamentXU123

Zend/zend_string.h

@@ -316,8 +316,8 @@ static zend_always_inline zend_string *zend_string_safe_realloc(zend_string *s,
 	return ret;
 }
 
-static zend_always_inline char *zend_str_append_char_to_raw(const char *str, size_t len, char c) {
-    char *res = (char *)emalloc(len + 2);
+static zend_always_inline char *zend_string_append_char_to_raw(const char *str, size_t len, char c) {
+    char *res = (char *)safe_emalloc(len, 1, 2);
     if (len > 0) {
         memcpy(res, str, len);
     }
@@ -326,8 +326,8 @@ static zend_always_inline char *zend_str_append_char_to_raw(const char *str, siz
     return res;
 }
 
-static zend_always_inline char *zend_str_concat_to_raw(const char *s1, size_t len1, const char *s2, size_t len2) {
-    char *res = (char *)emalloc(len1 + len2 + 1);
+static zend_always_inline char *zend_string_concat_to_raw(const char *s1, size_t len1, const char *s2, size_t len2) {
+    char *res = (char *)safe_emalloc(len1, 1, len2 + 1);
     if (len1 > 0) {
         memcpy(res, s1, len1);
     }
@@ -338,9 +338,8 @@ static zend_always_inline char *zend_str_concat_to_raw(const char *s1, size_t le
     return res;
 }
 
-static zend_always_inline char *zend_str_concat3_to_raw(const char *s1, size_t len1, const char *s2, size_t len2, const char *s3, size_t len3) {
-    size_t total_len = len1 + len2 + len3;
-    char *res = (char *)emalloc(total_len + 1);
+static zend_always_inline char *zend_string_concat3_to_raw(const char *s1, size_t len1, const char *s2, size_t len2, const char *s3, size_t len3) {
+    char *res = (char *)safe_emalloc(len1, 1, len2 + len3 + 1);
     if (len1 > 0) {
         memcpy(res, s1, len1);
     }
@@ -350,7 +349,7 @@ static zend_always_inline char *zend_str_concat3_to_raw(const char *s1, size_t l
     if (len3 > 0) {
         memcpy(res + len1 + len2, s3, len3);
     }
-    res[total_len] = '\0';
+    res[len1 + len2 + len3] = '\0';
     return res;
 }