Allow to use temporary strings in configTime (#8606)

Author: mcspr

cores/esp8266/Arduino.h

@@ -269,10 +269,13 @@ long map(long, long, long, long, long);
 
 void setTZ(const char* tz);
 
-void configTime(int timezone, int daylightOffset_sec, const char* server1,
+// configure time using POSIX TZ string
+// server pointers *must remain valid* for the duration of the program
+void configTime(const char* tz, const char* server1,
     const char* server2 = nullptr, const char* server3 = nullptr);
 
-void configTime(const char* tz, const char* server1,
+// configures with approximated TZ value. part of the old api, prefer configTime with TZ variable
+void configTime(int timezone, int daylightOffset_sec, const char* server1,
     const char* server2 = nullptr, const char* server3 = nullptr);
 
 // esp32 api compatibility
@@ -290,6 +293,12 @@ bool getLocalTime(struct tm * info, uint32_t ms = 5000);
 #include "WCharacter.h"
 #include "WString.h"
 
+// configTime wrappers for temporary server{1,2,3} strings
+void configTime(int timezone, int daylightOffset_sec, String server1,
+    String server2 = String(), String server3 = String());
+void configTime(const char* tz, String server1,
+    String server2 = String(), String server3 = String());
+
 #include "HardwareSerial.h"
 #include "Esp.h"
 #include "Updater.h"

cores/esp8266/time.cpp

@@ -208,6 +208,19 @@ void configTime(int timezone_sec, int daylightOffset_sec, const char* server1, c
     sntp_init();
 }
 
+void configTime(int timezone_sec, int daylightOffset_sec, String server1, String server2, String server3)
+{
+    static String servers[3];
+    servers[0] = std::move(server1);
+    servers[1] = std::move(server2);
+    servers[2] = std::move(server3);
+
+    configTime(timezone_sec, daylightOffset_sec,
+        servers[0].length() ? servers[0].c_str() : nullptr,
+        servers[1].length() ? servers[1].c_str() : nullptr,
+        servers[2].length() ? servers[2].c_str() : nullptr);
+}
+
 void setTZ(const char* tz){
 
     char tzram[strlen_P(tz) + 1];
@@ -228,6 +241,19 @@ void configTime(const char* tz, const char* server1, const char* server2, const
     sntp_init();
 }
 
+void configTime(const char* tz, String server1, String server2, String server3)
+{
+    static String servers[3];
+    servers[0] = std::move(server1);
+    servers[1] = std::move(server2);
+    servers[2] = std::move(server3);
+
+    configTime(tz,
+        servers[0].length() ? servers[0].c_str() : nullptr,
+        servers[1].length() ? servers[1].c_str() : nullptr,
+        servers[2].length() ? servers[2].c_str() : nullptr);
+}
+
 static BoolCB _settimeofday_cb;
 
 void settimeofday_cb (const TrivialCB& cb)