From cfd54af70070dfef30dd783eb3e4bb9d82f83e0c Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Thu, 28 May 2026 12:43:09 +0200
Subject: [PATCH] macOS: force fresh exFAT layout when formatting volumes

Pass -R to newfs_exfat in both GUI and text-mode volume creation so macOS derives a fresh exFAT layout instead of preserving stale geometry from an existing exFAT boot region. This matches Finder/Disk Utility erase behavior.

Validated on Windows 11: chkdsk no longer reports boot-region corruption on volumes formatted this way.

Fixes #1021.
---
 src/Main/Forms/VolumeCreationWizard.cpp |  3 +++
 src/Main/MacOSXFormatterDevice.h        | 21 ++++++++++++++++++---
 src/Main/TextUserInterface.cpp          |  3 +++
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/Main/Forms/VolumeCreationWizard.cpp b/src/Main/Forms/VolumeCreationWizard.cpp
index 9f50d258..6f1001e6 100644
--- a/src/Main/Forms/VolumeCreationWizard.cpp
+++ b/src/Main/Forms/VolumeCreationWizard.cpp
@@ -907,6 +907,9 @@ namespace VeraCrypt
 					}
 
 #ifdef TC_MACOSX
+					if (IsMacOSXExFATFormatter (fsFormatter))
+						AddMacOSXExFATFormatterArgs (args);
+
 					if (IsMacOSXAPFSFormatter (fsFormatter) && !useElevatedAPFSFormatter)
 						AddMacOSXAPFSFormatterUserArgs (args);
 #endif
diff --git a/src/Main/MacOSXFormatterDevice.h b/src/Main/MacOSXFormatterDevice.h
index d09337a3..a62898f6 100644
--- a/src/Main/MacOSXFormatterDevice.h
+++ b/src/Main/MacOSXFormatterDevice.h
@@ -61,11 +61,20 @@ namespace VeraCrypt
 		return deviceIdentifier;
 	}
 
-	inline bool IsMacOSXAPFSFormatter (const string &fsFormatter)
+	inline string GetMacOSXFormatterName (const string &fsFormatter)
 	{
 		size_t namePos = fsFormatter.find_last_of ('/');
-		string fsFormatterName = namePos == string::npos ? fsFormatter : fsFormatter.substr (namePos + 1);
-		return fsFormatterName == "newfs_apfs";
+		return namePos == string::npos ? fsFormatter : fsFormatter.substr (namePos + 1);
+	}
+
+	inline bool IsMacOSXAPFSFormatter (const string &fsFormatter)
+	{
+		return GetMacOSXFormatterName (fsFormatter) == "newfs_apfs";
+	}
+
+	inline bool IsMacOSXExFATFormatter (const string &fsFormatter)
+	{
+		return GetMacOSXFormatterName (fsFormatter) == "newfs_exfat";
 	}
 
 	inline bool UseElevatedMacOSXAPFSFormatter (const string &fsFormatter)
@@ -88,6 +97,12 @@ namespace VeraCrypt
 		args.push_back (gid.str());
 	}
 
+	inline void AddMacOSXExFATFormatterArgs (list <string> &args)
+	{
+		// Match Disk Utility/Finder erase behavior by deriving a fresh exFAT layout.
+		args.push_back ("-R");
+	}
+
 	struct MacOSXFormatterDeviceOwnerRestore
 	{
 		MacOSXFormatterDeviceOwnerRestore (const FilesystemPath &path, const UserId &owner)
diff --git a/src/Main/TextUserInterface.cpp b/src/Main/TextUserInterface.cpp
index defefafc..2d8871f8 100644
--- a/src/Main/TextUserInterface.cpp
+++ b/src/Main/TextUserInterface.cpp
@@ -1136,6 +1136,9 @@ namespace VeraCrypt
 			}
 
 #ifdef TC_MACOSX
+			if (IsMacOSXExFATFormatter (fsFormatter))
+				AddMacOSXExFATFormatterArgs (args);
+
 			if (IsMacOSXAPFSFormatter (fsFormatter) && !useElevatedAPFSFormatter)
 				AddMacOSXAPFSFormatterUserArgs (args);
 #endif