From 0f99110ee7d0e348b13748c48c4c5929e4a36010 Mon Sep 17 00:00:00 2001
From: lilei19 <lilei19@xiaomi.com>
Date: Tue, 21 Feb 2023 19:40:24 +0800
Subject: [PATCH] fix a bug of strtof

---
 libs/libc/stdlib/lib_strtold.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libs/libc/stdlib/lib_strtold.c b/libs/libc/stdlib/lib_strtold.c
index 2bc5b9002f451..a43212d3cb4f4 100644
--- a/libs/libc/stdlib/lib_strtold.c
+++ b/libs/libc/stdlib/lib_strtold.c
@@ -335,7 +335,8 @@ static long_double decfloat(FAR char *ptr, FAR char **endptr)
         }
     }
 
-  if ((c | 32) == 'e')
+  if ((c | 32) == 'e' && (isdigit(*f) || ((*f == '+' || *f == '-') &&
+                                          (isdigit(*(f + 1))))))
     {
       num_decimal = scanexp(&f, 1) + num_decimal;
       if (num_decimal <= llong_min / 100)