Fix "Select & Find Next" command not working regression

Regression introduced by:
be59048c5e (diff-ce3b24898ed0287ecacacc4d6c1712fb9eaf1ed67b36fd87315b8e80950de03aL1463)

Fix #17200, close #17206

PowerEditor/src/NppCommands.cpp

@@ -1443,8 +1443,8 @@ void Notepad_plus::command(int id)
 			if (isFirstTime)
 				_findReplaceDlg.doDialog(FIND_DLG, _nativeLangSpeaker.isRTL(), false);
 
-			const wchar_t* str = _findReplaceDlg.setSearchTextWithSettings();
+			wstring str = _findReplaceDlg.setSearchText();
-			if (!str) return;
+			if (str.empty()) return;
 
 			_findReplaceDlg._env->_str2Search = str;
 
@@ -1457,7 +1457,7 @@ void Notepad_plus::command(int id)
 			op._whichDirection = (id == IDM_SEARCH_SETANDFINDNEXT?DIR_DOWN:DIR_UP);
 
 			FindStatus status = FSNoMessage;
-			_findReplaceDlg.processFindNext(str, &op, &status);
+			_findReplaceDlg.processFindNext(str.c_str(), &op, &status);
 			if (status == FSEndReached)
 			{
 				wstring msg = _nativeLangSpeaker.getLocalizedStrFromID("find-status-end-reached", FIND_STATUS_END_REACHED_TEXT);

PowerEditor/src/ScintillaComponent/FindReplaceDlg.cpp

@@ -5375,10 +5375,27 @@ bool FindReplaceDlg::replaceInOpenDocsConfirmCheck()
 	return confirmed;
 }
 
-// return NULL if nothing to set in find field.
+// Expand selection (if needed) and set the selected text in Find What field.
-// Otherwise return string pointer (wchar_t *) in which the selected text was copied.
+// Return empty string if nothing to set in find field.
-// Note that the string pointer don't need to and should not be deallocated.
+// Otherwise return string in which the selected text was copied.
-const wchar_t* FindReplaceDlg::setSearchTextWithSettings()
+wstring FindReplaceDlg::setSearchText()
+{
+	const NppGUI& nppGui = NppParameters::getInstance().getNppGUI();
+	Sci_Position selStrCharNum = 0;
+	const wchar_t* selStr = (*_ppEditView)->getSelectedTextToWChar(true, &selStrCharNum);
+
+	if (selStr && selStrCharNum <= nppGui._fillFindWhatThreshold)
+	{
+		setSearchText(selStr);
+		return selStr;
+	}
+	return L"";
+}
+
+// Set the selected text in Find What field, according the Search settings.
+// Return empty string if nothing to set in find field.
+// Otherwise return string in which the selected text was copied.
+wstring FindReplaceDlg::setSearchTextWithSettings()
 {
 	const NppGUI& nppGui = NppParameters::getInstance().getNppGUI();
 	if (nppGui._fillFindFieldWithSelected)
@@ -5392,7 +5409,7 @@ const wchar_t* FindReplaceDlg::setSearchTextWithSettings()
 			return selStr;
 		}
 	}
-	return nullptr;
+	return L"";
 }
 
 wstring Finder::getHitsString(int count) const

PowerEditor/src/ScintillaComponent/FindReplaceDlg.h

@@ -419,7 +419,8 @@ public :
 	DIALOG_TYPE getCurrentStatus() { return _currentStatus; }
 	Finder* getFinderFrom(HWND hwnd);
 	int regexBackwardMsgBox();
-	const wchar_t* setSearchTextWithSettings();
+	std::wstring setSearchText();
+	std::wstring setSearchTextWithSettings();
 
 protected :
 	void resizeDialogElements();