From f75f8b8d40912bca6f501c2664ef93aa8ec2a9ab Mon Sep 17 00:00:00 2001
From: Scott Sumner <30118311+sasumner@users.noreply.github.com>
Date: Sun, 8 Nov 2020 08:49:28 -0500
Subject: [PATCH] Prevent names of untitled tabs from duplication

Fix #9119, close #9127
---
 PowerEditor/installer/nativeLang/english.xml |  1 +
 PowerEditor/src/NppIO.cpp                    | 43 ++++++++++++++------
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/PowerEditor/installer/nativeLang/english.xml b/PowerEditor/installer/nativeLang/english.xml
index 4ba4201d..08bdd7f1 100644
--- a/PowerEditor/installer/nativeLang/english.xml
+++ b/PowerEditor/installer/nativeLang/english.xml
@@ -1119,6 +1119,7 @@ Continue?"/> <!-- HowToReproduce: when you openned file is modified and saved, t
             <DocReloadWarning title="Reload" message="Are you sure you want to reload the current file and lose the changes made in Notepad++?"/>
             <FileLockedWarning title="Save failed" message="Please check whether if this file is opened in another program"/>
             <FileAlreadyOpenedInNpp title="" message="The file is already opened in Notepad++."/> <!-- HowToReproduce: Open a new document and open a file "c:/tmp/foo", save this new document by choosing "c:/tmp/foo" as file to save, reply the override popup "yes", then this message appears. -->
+            <RenameTabTemporaryNameAlreadyInUse title="Rename failed" message="The specified name is already in use on another tab."/> <!-- HowToReproduce: Rename the tab of an untitled document and provide a name that is the same as an already-existing tab of an untitled document. -->
             <DeleteFileFailed title="Delete File" message="Delete File failed"/> <!-- HowToReproduce: this message prevents from system failure. It's hard to reproduce. -->
 
             <NbFileToOpenImportantWarning title="Amount of files to open is too large" message="$INT_REPLACE$ files are about to be opened.
diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index a56c7c0f..007b0667 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -1741,23 +1741,40 @@ bool Notepad_plus::fileRename(BufferID id)
 		TCHAR *tabNewName = reinterpret_cast<TCHAR *>(strDlg.doDialog());
 		if (tabNewName)
 		{
-			success = true;
-			buf->setFileName(tabNewName);
-			bool isSnapshotMode = NppParameters::getInstance().getNppGUI().isSnapshotMode();
-			if (isSnapshotMode)
+			BufferID sameNamedBufferId = _pDocTab->findBufferByName(tabNewName);
+			if (sameNamedBufferId == BUFFER_INVALID)
 			{
-				generic_string oldBackUpFile = buf->getBackupFileName();
+				sameNamedBufferId = _pNonDocTab->findBufferByName(tabNewName);
+			}
+			
+			if (sameNamedBufferId != BUFFER_INVALID)
+			{
+				_nativeLangSpeaker.messageBox("RenameTabTemporaryNameAlreadyInUse",
+					_pPublicInterface->getHSelf(),
+					TEXT("The specified name is already in use on another tab."),
+					TEXT("Rename failed"),
+					MB_OK | MB_ICONSTOP);
+			}
+			else
+			{
+				success = true;
+				buf->setFileName(tabNewName);
+				bool isSnapshotMode = NppParameters::getInstance().getNppGUI().isSnapshotMode();
+				if (isSnapshotMode)
+				{
+					generic_string oldBackUpFile = buf->getBackupFileName();
 
-				// Change the backup file name and let MainFileManager decide the new filename
-				buf->setBackupFileName(TEXT(""));
+					// Change the backup file name and let MainFileManager decide the new filename
+					buf->setBackupFileName(TEXT(""));
 
-				// Create new backup
-				buf->setModifiedStatus(true);
-				bool bRes = MainFileManager.backupCurrentBuffer();
+					// Create new backup
+					buf->setModifiedStatus(true);
+					bool bRes = MainFileManager.backupCurrentBuffer();
 
-				// Delete old backup
-				if (bRes)
-					::DeleteFile(oldBackUpFile.c_str());
+					// Delete old backup
+					if (bRes)
+						::DeleteFile(oldBackUpFile.c_str());
+				}
 			}
 		}
 	}