Address review comments

Author: Girgias

ext/standard/mail.c

@@ -438,7 +438,7 @@ PHPAPI bool php_mail(const char *to, const char *subject, const char *message, c
 {
 	FILE *sendmail;
 	const char *sendmail_path = zend_ini_string_literal("sendmail_path");
-	char *sendmail_cmd = NULL;
+	const char *sendmail_cmd = NULL;
 	const zend_string *mail_log = zend_ini_str_literal("mail.log");
 	const char *hdr = headers;
 	char *ahdr = NULL;
@@ -553,7 +553,7 @@ PHPAPI bool php_mail(const char *to, const char *subject, const char *message, c
 	if (extra_cmd != NULL) {
 		spprintf(&sendmail_cmd, 0, "%s %s", sendmail_path, ZSTR_VAL(extra_cmd));
 	} else {
-		sendmail_cmd = (char*)sendmail_path;
+		sendmail_cmd = sendmail_path;
 	}
 
 #if PHP_SIGCHILD
@@ -576,7 +576,7 @@ PHPAPI bool php_mail(const char *to, const char *subject, const char *message, c
 	sendmail = popen(sendmail_cmd, "w");
 #endif
 	if (extra_cmd != NULL) {
-		efree (sendmail_cmd);
+		efree((char*)sendmail_cmd);
 	}
 
 	if (sendmail) {

ext/zlib/zlib.c

@@ -1280,7 +1280,7 @@ static PHP_INI_MH(OnUpdate_zlib_output_compression)
 	}
 	const zend_string *ini_value = zend_ini_str_literal("output_handler");
 
-	if (ini_value && ZSTR_LEN(ini_value) && int_value) {
+	if (ini_value && ZSTR_LEN(ini_value) > 0 && int_value) {
 		php_error_docref("ref.outcontrol", E_CORE_ERROR, "Cannot use both zlib.output_compression and output_handler together!!");
 		return FAILURE;
 	}

sapi/phpdbg/phpdbg_prompt.c

@@ -1194,9 +1194,9 @@ PHPDBG_API const char *phpdbg_load_module_or_extension(char **path, const char *
 
 	if (strchr(*path, '/') != NULL || strchr(*path, DEFAULT_SLASH) != NULL) {
 		/* path is fine */
-	} else if (extension_dir && ZSTR_LEN(extension_dir)) {
+	} else if (extension_dir && ZSTR_LEN(extension_dir) > 0) {
 		char *libpath;
-		if (IS_SLASH(ZSTR_VAL(extension_dir)[ZSTR_LEN(extension_dir-1)])) {
+		if (IS_SLASH(ZSTR_VAL(extension_dir)[ZSTR_LEN(extension_dir)-1])) {
 			spprintf(&libpath, 0, "%s%s", ZSTR_VAL(extension_dir), *path); /* SAFE */
 		} else {
 			spprintf(&libpath, 0, "%s%c%s", ZSTR_VAL(extension_dir), DEFAULT_SLASH, *path); /* SAFE */