Subject: [PATCH] make file merging respect permissions

From: James Bottomley <[email-masked]>
Date: Sat, 23 Apr 2005 14:22:50 -0400

I noticed when playing about with merging that executable scripts lose
their permissions after a merge.  This was because unpack-file just
unpacks to whatever the current umask is.

I also noticed that the merge-one-file-script thinks that if the file
has been removed in both branches, then it should simply be removed.
This isn't correct.  The file could have been renamed to something
different in both branches, in which case we have an unflagged rename
conflict.

The attached fixes both issues

James

--- a/git-merge-one-file-script
+++ b/git-merge-one-file-script
@@ -20,23 +20,47 @@ mkdir -p "$dir"
 
 case "${1:-.}${2:-.}${3:-.}" in
 #
-# deleted in both, or deleted in one and unchanged in the other
+# deleted in both
+#
+"$1..")
+	echo "ERROR: $4 is removed in both branches"
+	echo "ERROR: This is a potential rename conflict"
+	exit 1;;
+#
+# deleted in one and unchanged in the other
 #
 "$1.." | "$1.$1" | "$1$1.")
 	rm -f -- "$4"
+	echo "Removing $4"
 	update-cache --remove -- "$4"
 	exit 0
 	;;
 
 #
-# added in one, or added identically in both
+# added in one
 #
-".$2." | "..$3" | ".$2$2")
-	mv $(unpack-file "${2:-$3}") $4
+".$2." | "..$3" )
+	echo "Adding $4 with perm $6$7"
+	mv $(unpack-file "$2$3") $4
+	chmod "$6$7" $4
 	update-cache --add -- $4
 	exit 0
 	;;
-
+#
+# Added in both (check for same permissions)
+#
+".$2$2")
+	if [ "$6" != "$7" ]; then
+		echo "ERROR:"
+		echo "ERROR: File $4 added in both branches, permissions conflict $6->$7"
+		echo "ERROR:"
+		exit 1
+	fi
+	echo "Adding $4 with perm $6"
+	mv $(unpack-file "$2") $4
+	chmod "$6" $4
+	update-cache --add -- $4
+	exit 0;;
 #
 # Modified in both, but differently ;(
 #
@@ -46,12 +70,21 @@ case "${1:-.}${2:-.}${3:-.}" in
 	src1=$(unpack-file $2)
 	src2=$(unpack-file $3)
 	merge "$src2" "$orig" "$src1"
-	if [ $? -ne 0 ]; then
-		echo Leaving conflict merge in $src2
+	ret=$?
+	if [ "$6" != "$7" ]; then
+		echo "ERROR: Permissions $5->$6->$7" don't match merging $src2"
+		if [ $ret -ne 0 ]; then
+			echo "ERROR: Leaving conflict merge in $src2"
+		fi
+		exit 1
+	fi
+	chmod -- "$6" "$src2"
+	if [ $ -ne 0 ]; then
+		echo "ERROR: Leaving conflict merge in $src2"
 		exit 1
 	fi
-	cp "$src2" "$4" && update-cache --add -- "$4" && exit 0
+	cp -- "$src2" "$4" && chmod -- "$6" "$4" &&  update-cache --add -- "$4" && exit 0
 	;;
 
 *)
--- a/merge-cache.c
+++ b/merge-cache.c
@@ -4,7 +4,7 @@
 #include "cache.h"
 
 static const char *pgm = NULL;
-static const char *arguments[5];
+static const char *arguments[8];
 
 static void run_program(void)
 {
@@ -18,6 +18,9 @@ static void run_program(void)
 			    arguments[2],
 			    arguments[3],
 			    arguments[4],
+			    arguments[5],
+			    arguments[6],
+			    arguments[7],
 			    NULL);
 		die("unable to execute '%s'", pgm);
 	}
@@ -36,9 +39,13 @@ static int merge_entry(int pos, const ch
 	arguments[2] = "";
 	arguments[3] = "";
 	arguments[4] = path;
+	arguments[5] = "";
+	arguments[6] = "";
+	arguments[7] = "";
 	found = 0;
 	do {
 		static char hexbuf[4][60];
+		static char ownbuf[4][60];
 		struct cache_entry *ce = active_cache[pos];
 		int stage = ce_stage(ce);
 
@@ -46,7 +53,9 @@ static int merge_entry(int pos, const ch
 			break;
 		found++;
 		strcpy(hexbuf[stage], sha1_to_hex(ce->sha1));
+		sprintf(ownbuf[stage], "%o", ntohl(ce->ce_mode) & (~S_IFMT));
 		arguments[stage] = hexbuf[stage];
+		arguments[stage + 4] = ownbuf[stage];
 	} while (++pos < active_nr);
 	if (!found)
 		die("merge-cache: %s not in the cache", path);