From f8513cdfa8f0b8e95e233b6045493053c7ba7cc5 Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@amcrypto.jp>
Date: Tue, 16 Jun 2026 09:56:12 +0900
Subject: [PATCH] Linux: fix install on merged usr systems

Install staged /usr child directories by merging their contents into existing destination directories instead of replacing them. This preserves /usr/sbin symlinks to bin on merged-/usr distributions while keeping traditional layouts working.

Fixes issue: https://github.com/veracrypt/VeraCrypt/issues/1764
---
 src/Main/Main.make | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/Main/Main.make b/src/Main/Main.make
index faa25fbb..a1680711 100755
--- a/src/Main/Main.make
+++ b/src/Main/Main.make
@@ -569,9 +569,26 @@ endif
 
 install: prepare
 ifneq "$(DESTDIR)" ""
-	mkdir -p $(DESTDIR)
+	mkdir -p "$(DESTDIR)"
 endif
-	cp -R $(BASE_DIR)/Setup/Linux/usr $(DESTDIR)/
+# Merge directory contents so /usr/sbin -> bin layouts are not replaced.
+	@set -e; \
+	mkdir -p "$(DESTDIR)/usr"; \
+	for _src in "$(BASE_DIR)/Setup/Linux/usr"/*; do \
+		[ -e "$$_src" ] || continue; \
+		_name=$$(basename "$$_src"); \
+		_dst="$(DESTDIR)/usr/$$_name"; \
+		if [ -d "$$_src" ]; then \
+			if [ -e "$$_dst" ] || [ -L "$$_dst" ]; then \
+				mkdir -p "$$_dst"; \
+				cp -R "$$_src/." "$$_dst/"; \
+			else \
+				cp -R "$$_src" "$(DESTDIR)/usr/"; \
+			fi; \
+		else \
+			cp -P "$$_src" "$(DESTDIR)/usr/"; \
+		fi; \
+	done
 
 ifeq "$(TC_BUILD_CONFIG)" "Release"
 package: prepare