Perform limited conflict checking with --force

Pacman currently bails when trying to extract a file over a directory
when using --force.  Instead of ignoring all conflict, perform the
check and skip any file-file conflicts. Conflicts between directories
and files are still flagged and cause the transation to abort.

As a bonus, we now know about files changing packages when using
--force, so we can skip removing them fixing upgrade046.

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

2 files changed, 27 insertions, 3 deletions

diff --git a/lib/libalpm/conflict.c b/lib/libalpm/conflict.c
index afed8953..18e29a89 100644
--- a/lib/libalpm/conflict.c
+++ b/lib/libalpm/conflict.c
@@ -443,8 +443,10 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 			alpm_list_t *common_files;
 			alpm_pkg_t *p2 = j->data;
 
-			common_files = _alpm_filelist_intersection(alpm_pkg_get_files(p1),
-					alpm_pkg_get_files(p2));
+			alpm_filelist_t *p1_files = alpm_pkg_get_files(p1);
+			alpm_filelist_t *p2_files = alpm_pkg_get_files(p2);
+
+			common_files = _alpm_filelist_intersection(p1_files, p2_files);
 
 			if(common_files) {
 				alpm_list_t *k;
@@ -452,6 +454,20 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 				for(k = common_files; k; k = k->next) {
 					char *filename = k->data;
 					snprintf(path, PATH_MAX, "%s%s", handle->root, filename);
+
+					/* can skip file-file conflicts when forced *
+					 * checking presence in p2_files detects dir-file or file-dir
+					 * conflicts as the path from p1 is returned */
+					if((handle->trans->flags & ALPM_TRANS_FLAG_FORCE) &&
+							alpm_filelist_contains(p2_files, filename)) {
+						_alpm_log(handle, ALPM_LOG_DEBUG,
+							"%s exists in both '%s' and '%s'\n", filename,
+							p1->name, p2->name);
+						_alpm_log(handle, ALPM_LOG_DEBUG,
+							"file-file conflict being forced\n");
+						continue;
+					}
+
 					conflicts = add_fileconflict(handle, conflicts, path, p1, p2);
 					if(handle->pm_errno == ALPM_ERR_MEMORY) {
 						FREELIST(conflicts);
@@ -606,6 +622,14 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 				}
 			}
 
+			/* skip file-file conflicts when being forced */
+			if((handle->trans->flags & ALPM_TRANS_FLAG_FORCE) &&
+					!S_ISDIR(lsbuf.st_mode)) {
+				_alpm_log(handle, ALPM_LOG_DEBUG,
+							"conflict with file on filesystem being forced\n");
+				resolved_conflict = 1;
+			}
+
 			if(!resolved_conflict) {
 				conflicts = add_fileconflict(handle, conflicts, path, p1, NULL);
 				if(handle->pm_errno == ALPM_ERR_MEMORY) {
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index f7b956ca..204456d6 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -1241,7 +1241,7 @@ int _alpm_sync_commit(alpm_handle_t *handle, alpm_list_t **data)
 	trans->state = STATE_COMMITING;
 
 	/* fileconflict check */
-	if(!(trans->flags & (ALPM_TRANS_FLAG_FORCE|ALPM_TRANS_FLAG_DBONLY))) {
+	if(!(trans->flags & ALPM_TRANS_FLAG_DBONLY)) {
 		EVENT(handle, ALPM_EVENT_FILECONFLICTS_START, NULL, NULL);
 
 		_alpm_log(handle, ALPM_LOG_DEBUG, "looking for file conflicts\n");