[pacman-dev] [PATCH 1/2] always unlink files before extraction

[Andrew Gregory]

libarchive will not extract a directory over an existing directory
symlink, making it impossible to replace a symlink with a directory
across packages.  Adding the ARCHIVE_EXTRACT_UNLINK and
ARCHIVE_EXTRACT_SECURE_SYMLINKS causes libarchive to unlink the existing
symlink and prevents it from extracting any paths that contain
a symlink, which we should not be doing anyway.

Signed-off-by: Andrew Gregory <andrew.gregory.8 at gmail.com>
---
 lib/libalpm/add.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index 2684e94..63eda49 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -112,7 +112,9 @@ static int perform_extraction(alpm_handle_t *handle, struct archive *archive,
 	int ret;
 	const int archive_flags = ARCHIVE_EXTRACT_OWNER |
 	                          ARCHIVE_EXTRACT_PERM |
-	                          ARCHIVE_EXTRACT_TIME;
+	                          ARCHIVE_EXTRACT_TIME |
+	                          ARCHIVE_EXTRACT_UNLINK |
+	                          ARCHIVE_EXTRACT_SECURE_SYMLINKS;
 
 	archive_entry_set_pathname(entry, filename);
 
@@ -301,13 +303,6 @@ static int extract_single_file(alpm_handle_t *handle, struct archive *archive,
 		strcpy(filename + filename_len, ".pacnew");
 	}
 
-	if(handle->trans->flags & ALPM_TRANS_FLAG_FORCE) {
-		/* if FORCE was used, unlink() each file (whether it's there
-		 * or not) before extracting. This prevents the old "Text file busy"
-		 * error that crops up if forcing a glibc or pacman upgrade. */
-		unlink(filename);
-	}
-
 	_alpm_log(handle, ALPM_LOG_DEBUG, "extracting %s\n", filename);
 	if(perform_extraction(handle, archive, entry, filename)) {
 		errors++;
-- 
2.6.3