From 4c0a85ba0f18f59d4482f398d772e8a0907cde84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Sch=C3=BCler-Maroldt?=
 <joerg@schueler-maroldt.de>
Date: Sat, 25 Apr 2020 00:55:39 +0200
Subject: [PATCH] CommandHandler() optimize and maybe security fix

---
 tasmota/support_command.ino | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/tasmota/support_command.ino b/tasmota/support_command.ino
index a60a57b4c..6a8608560 100644
--- a/tasmota/support_command.ino
+++ b/tasmota/support_command.ino
@@ -204,14 +204,19 @@ void CommandHandler(char* topicBuf, char* dataBuf, uint32_t data_len)
   if (type != nullptr) {
     type++;
     uint32_t i;
-    for (i = 0; i < strlen(type); i++) {
-      type[i] = toupper(type[i]);
+    int nLen; // strlen(type)
+    char *s = type;
+    for (nLen = 0; *s; s++, nLen++) {
+      *s=toupper(*s);
     }
-    while (isdigit(type[i-1])) {
-      i--;
+    i = nLen;
+    if (i > 0) { // may be 0
+      while (isdigit(type[i-1])) {
+        i--;
+      }
     }
-    if (i < strlen(type)) {
-      index = atoi(type +i);
+    if (i < nLen) {
+      index = atoi(type + i);
       user_index = true;
     }
     type[i] = '\0';