[pacman-dev] [PATCH] It turns out we do care about directories...

[Allan McRae]

This is a bug that has been around for over a year now.  On a package
upgrade (either by -S or -U) a new directory could overwrite any file.
This is caused by the filelist difference calculation ignoring all
directories and thus no new directories were checked for conflicting
files on the filesystem.

Signed-off-by: Allan McRae <allan at archlinux.org>
---

I saw the comment was added to that code in 2011, but I think this issue
has been around for a very long time before that.

Please look at the patch and give it an ack somewhat urgently.  I intend
to backport to the Arch Linux pacman package.

 lib/libalpm/filelist.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/lib/libalpm/filelist.c b/lib/libalpm/filelist.c
index bf7645b..f8a5258 100644
--- a/lib/libalpm/filelist.c
+++ b/lib/libalpm/filelist.c
@@ -228,23 +228,17 @@ alpm_list_t *_alpm_filelist_difference(alpm_filelist_t *filesA,
 		alpm_file_t *fileA = filesA->files + ctrA;
 		const char *strA = filesA->resolved_path[ctrA];
 		const char *strB = filesB->resolved_path[ctrB];
-		/* skip directories, we don't care about them */
-		if(strA[strlen(strA)-1] == '/') {
+
+		int cmp = strcmp(strA, strB);
+		if(cmp < 0) {
+			/* item only in filesA, qualifies as a difference */
+			ret = alpm_list_add(ret, fileA);
 			ctrA++;
-		} else if(strB[strlen(strB)-1] == '/') {
+		} else if(cmp > 0) {
 			ctrB++;
 		} else {
-			int cmp = strcmp(strA, strB);
-			if(cmp < 0) {
-				/* item only in filesA, qualifies as a difference */
-				ret = alpm_list_add(ret, fileA);
-				ctrA++;
-			} else if(cmp > 0) {
-				ctrB++;
-			} else {
-				ctrA++;
-				ctrB++;
-			}
+			ctrA++;
+			ctrB++;
 		}
 	}
 
-- 
1.8.0.1