From 16c2929bb401d4665155354751ff148751f16980 Mon Sep 17 00:00:00 2001
From: Otto Winter <otto@otto-winter.com>
Date: Fri, 24 May 2019 19:32:59 +0200
Subject: [PATCH] Fix parse_float accepting invalid input

---
 esphome/core/helpers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/esphome/core/helpers.cpp b/esphome/core/helpers.cpp
index 769a7825da..c65ca919ba 100644
--- a/esphome/core/helpers.cpp
+++ b/esphome/core/helpers.cpp
@@ -257,7 +257,7 @@ std::string to_string(long double val) {
 optional<float> parse_float(const std::string &str) {
   char *end;
   float value = ::strtof(str.c_str(), &end);
-  if (end == nullptr)
+  if (end == nullptr || end != str.end().base())
     return {};
   return value;
 }