Merge remote-tracking branch 'public/pr/1145' into development

* public/pr/1145:
  Address PR review comments
  Fix crash when calling `mbedtls_ssl_cache_free` twice

ChangeLog

@@ -54,6 +54,8 @@ Bugfix
      Reported by Yolan Romailler.
    * Fix word size check in in pk.c to not depend on MBEDTLS_HAVE_INT64.
    * Fix incorrect unit in benchmark output. #850
+   * Fix crash when calling mbedtls_ssl_cache_free() twice. Found by
+     MilenkoMitrovic, #1104
 
 Changes
    * Extend cert_write example program by options to set the CRT version

library/ssl_cache.c

@@ -321,6 +321,7 @@ void mbedtls_ssl_cache_free( mbedtls_ssl_cache_context *cache )
 #if defined(MBEDTLS_THREADING_C)
     mbedtls_mutex_free( &cache->mutex );
 #endif
+    cache->chain = NULL;
 }
 
 #endif /* MBEDTLS_SSL_CACHE_C */