[Memory] Free allocated memory in Strings .clear() does not free it

See: https://github.com/esp8266/Arduino/issues/8485

src/_C008.cpp

@@ -49,7 +49,7 @@ bool CPlugin_008(CPlugin::Function function, struct EventStruct *event, String&
 
     case CPlugin::Function::CPLUGIN_PROTOCOL_TEMPLATE:
     {
-      event->String1.clear();
+      event->String1 = String();
       event->String2 = F("demo.php?name=%sysname%&task=%tskname%&valuename=%valname%&value=%value%");
       break;
     }

src/_C010.cpp

@@ -35,7 +35,7 @@ bool CPlugin_010(CPlugin::Function function, struct EventStruct *event, String&
 
     case CPlugin::Function::CPLUGIN_PROTOCOL_TEMPLATE:
     {
-      event->String1.clear();
+      event->String1 = String();
       event->String2 = F("%sysname%_%tskname%_%valname%=%value%");
       break;
     }

src/_C016.cpp

@@ -104,8 +104,8 @@ bool CPlugin_016(CPlugin::Function function, struct EventStruct *event, String&
 
     case CPlugin::Function::CPLUGIN_PROTOCOL_TEMPLATE:
     {
-      event->String1.clear();
-      event->String2.clear();
+      event->String1 = String();
+      event->String2 = String();
       break;
     }
 

src/_C018.cpp

@@ -48,9 +48,9 @@ struct C018_data_struct {
       delete C018_easySerial;
       C018_easySerial = nullptr;
     }
-    cacheDevAddr.clear();
-    cacheHWEUI.clear();
-    cacheSysVer.clear();
+    cacheDevAddr = String();
+    cacheHWEUI = String();
+    cacheSysVer = String();
     autobaud_success = false;
   }
 
@@ -353,7 +353,7 @@ private:
   }
 
   void updateCacheOnInit() {
-    cacheDevAddr.clear();
+    cacheDevAddr = String();
 
     if (isInitialized()) {
       if (myLora->getStatus().Joined)
@@ -361,7 +361,7 @@ private:
         cacheDevAddr = myLora->sendRawCommand(F("mac get devaddr"));
 
         if (cacheDevAddr == F("00000000")) {
-          cacheDevAddr.clear();
+          cacheDevAddr = String();
         }
       }
     }

src/_P016_IR.ino

@@ -378,7 +378,7 @@ boolean Plugin_016(uint8_t function, struct EventStruct *event, String& string)
             html_TD();
             addCheckBox(getPluginCustomArgName(rowCnt + 1), bitRead(line.CodeFlags, P16_FLAGS_REPEAT));
             html_TD();
-            strCode.clear();
+            strCode = String();
 
             if (line.Code > 0) {
               strCode = uint64ToString(line.Code, 16); // convert code to hex for display
@@ -393,7 +393,7 @@ boolean Plugin_016(uint8_t function, struct EventStruct *event, String& string)
             html_TD();
             addCheckBox(getPluginCustomArgName(rowCnt + 4), bitRead(line.AlternativeCodeFlags, P16_FLAGS_REPEAT));
             html_TD();
-            strCode.clear();
+            strCode = String();
 
             if (line.AlternativeCode > 0) {
               strCode = uint64ToString(line.AlternativeCode, 16); // convert code to hex for display
@@ -462,7 +462,7 @@ boolean Plugin_016(uint8_t function, struct EventStruct *event, String& string)
           for (uint8_t varNr = 0; varNr < P16_Nlines; varNr++) {
             tCommandLinesV2 line;
 
-            strError.clear();
+            strError = String();
 
             // Normal Code & flags
             line.CodeDecodeType = static_cast<decode_type_t>(getFormItemInt(getPluginCustomArgName(rowCnt + 0)));

src/_P055_Chiming.ino

@@ -490,7 +490,7 @@ uint8_t Plugin_055_ReadChime(const String& name, String& tokens)
   log += fileName;
   log += ' ';
 
-  tokens.clear();
+  tokens = String();
   fs::File f = tryOpenFile(fileName, "r");
   if (f)
   {

src/src/Commands/InternalCommands.cpp

@@ -176,7 +176,7 @@ bool do_command_case_check(command_case_data         & data,
   // The data struct is re-used on each attempt to process an internal command.
   // Re-initialize the only two members that may have been altered by a previous call.
   data.retval = false;
-  data.status.clear();
+  data.status = String();
   if (!data.cmd_lc.equals(cmd_test)) {
     return false;
   }

src/src/DataStructs/Modbus.cpp

@@ -97,7 +97,7 @@ bool Modbus::handle() {
   unsigned int RXavailable = 0;
 
   #ifndef BUILD_NO_DEBUG
-  LogString.clear();
+  LogString = String();
   #endif
   int64_t rxValue = 0;
 

src/src/ESPEasyCore/ESPEasy_Log.cpp

@@ -300,5 +300,5 @@ void addToLogMove(uint8_t logLevel, String&& string)
     Logging.add(logLevel, std::move(string));
   }
   // Make sure the string may no longer keep up memory
-  string.clear();
+  string = String();
 }

src/src/Globals/RamTracker.cpp

@@ -81,7 +81,7 @@ RamTracker::RamTracker(void) {
   writePtr = 0;
 
   for (int i = 0; i < TRACES; i++) {
-    traces[i].clear();
+    traces[i] = String();
     tracesMemory[i] = 0xffffffff; // init with best case memory values, so they get replaced if memory goes lower
   }
 
@@ -97,7 +97,7 @@ void RamTracker::registerRamState(const String& s) {   // store function
   int bestCase = bestCaseTrace();                      // find best case memory trace
 
   if (ESP.getFreeHeap() < tracesMemory[bestCase]) {    // compare to current memory value
-    traces[bestCase].clear();
+    traces[bestCase] = String();
     readPtr          = writePtr + 1;                   // read out buffer, oldest value first
 
     if (readPtr >= TRACEENTRIES) { 
@@ -135,7 +135,7 @@ void RamTracker::getTraceBuffer() {
       retval += ' ';
       retval += traces[i];
       addLogMove(LOG_LEVEL_DEBUG_DEV, retval);
-      retval.clear();
+      retval = String();
     }
   }
 #endif // ifndef BUILD_NO_DEBUG

src/src/Helpers/ESPEasy_Storage.cpp

@@ -676,7 +676,7 @@ String LoadStringArray(SettingsType::Enum settingsType, int index, String string
             #endif
 
             strings[stringCount] = tmpString;
-            tmpString.clear();
+            tmpString = String();
             tmpString.reserve(estimatedStringSize);
             ++stringCount;
           } else {

src/src/Helpers/ESPEasy_checks.cpp

@@ -187,7 +187,7 @@ String ReportOffsetErrorInStruct(const String& structname, size_t offset) {
 *  Not a member function to be able to use the F-macro
 \*********************************************************************************************/
 bool SettingsCheck(String& error) {
-  error.clear();
+  error = String();
   #ifndef LIMIT_BUILD_SIZE
 #ifdef esp8266
   size_t offset = offsetof(SettingsStruct, ResetFactoryDefaultPreference);

src/src/Helpers/Modbus_RTU.cpp

@@ -19,7 +19,7 @@ void ModbusRTU_struct::reset() {
     delete easySerial;
     easySerial = nullptr;
   }
-  detected_device_description.clear();
+  detected_device_description = String();
 
   for (int i = 0; i < 8; ++i) {
     _sendframe[i] = 0;

src/src/Helpers/StringConverter.cpp

@@ -1092,7 +1092,7 @@ bool GetArgv(const char *string, String& argvString, unsigned int argc, char sep
   int  pos_begin, pos_end;
   bool hasArgument = GetArgvBeginEnd(string, argc, pos_begin, pos_end, separator);
 
-  argvString.clear();
+  argvString = String();
 
   if (!hasArgument) { return false; }
 

src/src/Helpers/StringParser.cpp

@@ -278,7 +278,7 @@ void transformValue(
             }
 
             if (value == F("0")) {
-              value.clear();
+              value = String();
             } else {
               const int valueLength = value.length();
 
@@ -666,7 +666,7 @@ bool findNextDevValNameInString(const String& input, int& startpos, int& endpos,
     format    = valueName.substring(hashpos + 1);
     valueName = valueName.substring(0, hashpos);
   } else {
-    format.clear();
+    format = String();
   }
   deviceName.toLowerCase();
   valueName.toLowerCase();

src/src/Helpers/WebServer_commandHelper.cpp

@@ -22,7 +22,7 @@ HandledWebCommand_result handle_command_from_web(EventValueSource::Enum source,
 
   bool handledCmd = false;
   bool sendOK     = false;
-  printWebString.clear();
+  printWebString = String();
   printToWeb     = false;
   printToWebJSON = false;
 

src/src/Helpers/_CPlugin_Helper.cpp

@@ -50,7 +50,7 @@ bool safeReadStringUntil(Stream     & input,
   const unsigned long timer           = start + timeout;
   unsigned long backgroundtasks_timer = start + 10;
 
-  str.clear();
+  str = String();
 
   do {
     // read character

src/src/PluginStructs/P020_data_struct.cpp

@@ -109,7 +109,7 @@ void P020_Task::discardClientIn() {
 }
 
 void P020_Task::clearBuffer() {
-  serial_buffer.clear();
+  serial_buffer = String();
   serial_buffer.reserve(P020_DATAGRAM_MAX_SIZE);
 }
 

src/src/PluginStructs/P044_data_struct.cpp

@@ -122,7 +122,7 @@ void P044_Task::clearBuffer() {
     maxMessageSize = _min(serial_buffer.length(), P044_DATAGRAM_MAX_SIZE);
   }
 
-  serial_buffer.clear();
+  serial_buffer = String();
   serial_buffer.reserve(maxMessageSize);
 }
 

src/src/PluginStructs/P073_data_struct.cpp

@@ -315,7 +315,7 @@ void P073_data_struct::NextScroll() {
 }
 
 void P073_data_struct::setTextToScroll(const String& text) {
-  _textToScroll.clear();
+  _textToScroll = String();
 
   if (!text.isEmpty()) {
     const int bufToFill = getBufferLength(displayModel);

src/src/PluginStructs/P082_data_struct.cpp

@@ -167,7 +167,7 @@ bool P082_data_struct::loop() {
           // Full sentence received
 # ifdef P082_SEND_GPS_TO_LOG
           _lastSentence    = _currentSentence;
-          _currentSentence.clear();
+          _currentSentence = String();
 # endif // ifdef P082_SEND_GPS_TO_LOG
           completeSentence = true;
         } else {

src/src/PluginStructs/P087_data_struct.cpp

@@ -108,7 +108,7 @@ bool P087_data_struct::loop() {
 
           for (size_t i = 0; i < length && valid; ++i) {
             if ((sentence_part[i] > 127) || (sentence_part[i] < 32)) {
-              sentence_part.clear();
+              sentence_part = String();
               ++sentences_received_error;
               valid = false;
             }
@@ -117,7 +117,7 @@ bool P087_data_struct::loop() {
           if (valid) {
             fullSentenceReceived = true;
             last_sentence = sentence_part;
-            sentence_part.clear();
+            sentence_part = String();
           }
           break;
         }
@@ -146,7 +146,7 @@ bool P087_data_struct::getSentence(String& string) {
   if (string.isEmpty()) {
     return false;
   }
-  last_sentence.clear();
+  last_sentence = String();
   return true;
 }
 

src/src/PluginStructs/P094_data_struct.cpp

@@ -114,7 +114,7 @@ bool P094_data_struct::loop() {
 
           for (size_t i = 0; i < length && valid; ++i) {
             if ((sentence_part[i] > 127) || (sentence_part[i] < 32)) {
-              sentence_part.clear();
+              sentence_part = String();
               ++sentences_received_error;
               valid = false;
             }
@@ -151,7 +151,7 @@ const String& P094_data_struct::peekSentence() const {
 
 void P094_data_struct::getSentence(String& string, bool appendSysTime) {
   string = std::move(sentence_part);
-  sentence_part.clear(); // FIXME TD-er: Should not be needed as move already cleared it.
+  sentence_part = String(); // FIXME TD-er: Should not be needed as move already cleared it.
   if (appendSysTime) {
     // Unix timestamp = 10 decimals + separator
     if (string.reserve(sentence_part.length() + 11)) {

src/src/PluginStructs/P104_data_struct.cpp

@@ -313,7 +313,7 @@ void P104_data_struct::loadSettings() {
         # endif // ifdef P104_DEBUG
       }
 
-      buffer.clear();        // Free some memory
+      buffer = String();        // Free some memory
     }
 
     delete[] settingsBuffer; // Release allocated buffer

src/src/WebServer/ControlPage.cpp

@@ -41,7 +41,7 @@ void handle_control() {
 
   TXBuffer.endStream();
 
-  printWebString.clear();
+  printWebString = String();
   printToWeb     = false;
   printToWebJSON = false;
 }

src/src/WebServer/CustomPage.cpp

@@ -153,7 +153,7 @@ bool handle_custom(const String& path) {
           line += c;
           if (c == '\n') {
             addHtml(parseTemplate(line));
-            line.clear();
+            line = String();
             line.reserve(128);
           }
         }

src/src/WebServer/RootPage.cpp

@@ -265,7 +265,7 @@ void handle_root() {
           addHtml(F("<TR><TD colspan='2'>Command Output<BR><textarea readonly rows='10' wrap='on'>"));
           addHtml(printWebString);
           addHtml(F("</textarea>"));
-          printWebString.clear();
+          printWebString = String();
         }
       }
       html_end_table();
@@ -342,7 +342,7 @@ void handle_root() {
       html_end_form();
     }
 
-    printWebString.clear();
+    printWebString = String();
     printToWeb     = false;
     sendHeadandTail_stdtemplate(_TAIL);
   }

src/src/WebServer/ToolsPage.cpp

@@ -57,7 +57,7 @@ void handle_tools() {
     addHtml(F("<TR><TD colspan='2'>Command Output<BR><textarea readonly rows='10' wrap='on'>"));
     addHtml(printWebString);
     addHtml(F("</textarea>"));
-    printWebString.clear();
+    printWebString = String();
   }
 
 
@@ -177,7 +177,7 @@ void handle_tools() {
   html_end_form();
   sendHeadandTail_stdtemplate(_TAIL);
   TXBuffer.endStream();
-  printWebString.clear();
+  printWebString = String();
   printToWeb     = false;
 }
 

src/src/WebServer/UploadPage.cpp

@@ -27,7 +27,7 @@ void handle_upload() {
             "<form enctype='multipart/form-data' method='post'><p>Upload settings file:<br><input type='file' name='datafile' size='40'></p><div><input class='button link' type='submit' value='Upload'></div><input type='hidden' name='edit' value='1'></form>"));
   sendHeadandTail_stdtemplate(true);
   TXBuffer.endStream();
-  printWebString.clear();
+  printWebString = String();
   printToWeb     = false;
 }
 
@@ -64,7 +64,7 @@ void handle_upload_post() {
   addHtml(F("Upload finished"));
   sendHeadandTail_stdtemplate(true);
   TXBuffer.endStream();
-  printWebString.clear();
+  printWebString = String();
   printToWeb     = false;
 }
 

src/src/WebServer/WebTemplateParser.cpp

@@ -130,7 +130,7 @@ bool WebTemplateParser::process(const char c) {
           } else if (Tail == contentVarFound) {
             processVarName();
           }
-          varName.clear();
+          varName = String();
         }
       }
       break;