From a5383fd2088d2622b30cfa23e45733b936e20059 Mon Sep 17 00:00:00 2001
From: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Date: Wed, 16 Jun 2021 13:49:06 +1200
Subject: [PATCH] Shorten the ble name to prevent crash with long device names
 (#1920)

---
 esphome/components/esp32_ble/ble.cpp | 11 ++++++++++-
 esphome/core/application.h           |  4 ++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/esphome/components/esp32_ble/ble.cpp b/esphome/components/esp32_ble/ble.cpp
index 18e80754df..d245cb9e4d 100644
--- a/esphome/components/esp32_ble/ble.cpp
+++ b/esphome/components/esp32_ble/ble.cpp
@@ -91,7 +91,16 @@ bool ESP32BLE::ble_setup_() {
     }
   }
 
-  err = esp_ble_gap_set_device_name(App.get_name().c_str());
+  std::string name = App.get_name();
+  if (name.length() > 20) {
+    if (App.is_name_add_mac_suffix_enabled()) {
+      name.erase(name.begin() + 13, name.end() - 7);  // Remove characters between 13 and the mac address
+    } else {
+      name = name.substr(0, 20);
+    }
+  }
+
+  err = esp_ble_gap_set_device_name(name.c_str());
   if (err != ESP_OK) {
     ESP_LOGE(TAG, "esp_ble_gap_set_device_name failed: %d", err);
     return false;
diff --git a/esphome/core/application.h b/esphome/core/application.h
index aeda245161..97c99bd4f9 100644
--- a/esphome/core/application.h
+++ b/esphome/core/application.h
@@ -38,6 +38,7 @@ namespace esphome {
 class Application {
  public:
   void pre_setup(const std::string &name, const char *compilation_time, bool name_add_mac_suffix) {
+    this->name_add_mac_suffix_ = name_add_mac_suffix;
     if (name_add_mac_suffix) {
       this->name_ = name + "-" + get_mac_address().substr(6);
     } else {
@@ -97,6 +98,8 @@ class Application {
   /// Get the name of this Application set by set_name().
   const std::string &get_name() const { return this->name_; }
 
+  bool is_name_add_mac_suffix_enabled() const { return this->name_add_mac_suffix_; }
+
   const std::string &get_compilation_time() const { return this->compilation_time_; }
 
   /** Set the target interval with which to run the loop() calls.
@@ -245,6 +248,7 @@ class Application {
 
   std::string name_;
   std::string compilation_time_;
+  bool name_add_mac_suffix_;
   uint32_t last_loop_{0};
   uint32_t loop_interval_{16};
   int dump_config_at_{-1};