Subject: Re: [PATCH] make file merging respect permissions

From: James Bottomley <[email-masked]>
Date: Sat, 23 Apr 2005 23:42:51 -0500

On Sat, 2005-04-23 at 18:01 -0700, Linus Torvalds wrote:
> 
> On Sat, 23 Apr 2005, James Bottomley wrote:
> > 
> > This is the actual diff
> 
> This is _still_ corrupted. 
> 
> Are you editing your diffs by hand without understanding how the diffs 
> work?

Sort of: I'm taking a diff between my tree and yours but stripping out
the extraneous pieces (which are whole file diffs, nothing in the actual
diffs I send you).

> The second chunk of the "git-merge-one-file" diff _still_ claims to change 
> twelve lines, and that diff _still_ only changes eleven lines. My "patch" 
> isn't happy, and I can count the lines in the diff myself and verify that 
> it's not patch that is wrong, it's your diff.
> 
> Please please _please_ don't edit diffs by hand if you don't know what 
> you're doing. Generate the diff from a clean source instead. Or ask me to 
> fix it up, I'm so used to editing diffs that I can do it in my sleep.

OK ... this is done by reapplying to the top of your git tree and then
doing a show-diff.  I've checked that it actually applies without
rejections to a pristine git tree.

James

git-merge-one-file-script: b2adc5fc4583e6089f4b38a47e1a73caad183f20
--- a/git-merge-one-file-script
+++ b/git-merge-one-file-script
@@ -20,23 +20,45 @@ 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: File $4 added in both branches, permissions conflict $6->$7"
+		exit 1
+	fi
+	echo "Adding $4 with perm $6"
+	mv $(unpack-file "$2") $4
+	chmod "$6" $4
+	update-cache --add -- $4
+	exit 0;;
 #
 # Modified in both, but differently ;(
 #
@@ -46,11 +68,20 @@ case "${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 [ $ret -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
 	;;
 
 *)
merge-cache.c: 68ac4ab2d926005a5a729017c1bcb70a30634bd8
--- 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);