do not rely on localdb for hook matching

Relying on localdb to determine which trigger operations should match is
completely broken for PostTransaction hooks because the localdb has
already been updated.  Store a copy of the old version of any packages
being updated to use instead.

Fixes FS#47996

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

lib/libalpm/add.c

@@ -409,9 +409,8 @@ static int commit_single_pkg(alpm_handle_t *handle, alpm_pkg_t *newpkg,
 	ASSERT(trans != NULL, return -1);
 
 	/* see if this is an upgrade. if so, remove the old package first */
-	alpm_pkg_t *local = _alpm_db_get_pkgfromcache(db, newpkg->name);
-	if(local) {
-		int cmp = _alpm_pkg_compare_versions(newpkg, local);
+	if((oldpkg = newpkg->oldpkg)) {
+		int cmp = _alpm_pkg_compare_versions(newpkg, oldpkg);
 		if(cmp < 0) {
 			log_msg = "downgrading";
 			progress = ALPM_PROGRESS_DOWNGRADE_START;
@@ -427,14 +426,8 @@ static int commit_single_pkg(alpm_handle_t *handle, alpm_pkg_t *newpkg,
 		}
 		is_upgrade = 1;
 
-		/* we'll need to save some record for backup checks later */
-		if(_alpm_pkg_dup(local, &oldpkg) == -1) {
-			ret = -1;
-			goto cleanup;
-		}
-
 		/* copy over the install reason */
-		newpkg->reason = alpm_pkg_get_reason(local);
+		newpkg->reason = alpm_pkg_get_reason(oldpkg);
 	} else {
 		event.operation = ALPM_PACKAGE_INSTALL;
 	}
@@ -630,7 +623,6 @@ static int commit_single_pkg(alpm_handle_t *handle, alpm_pkg_t *newpkg,
 	EVENT(handle, &event);
 
 cleanup:
-	_alpm_pkg_free(oldpkg);
 	return ret;
 }
 

lib/libalpm/hook.c

@@ -374,7 +374,7 @@ static int _alpm_hook_trigger_match_file(alpm_handle_t *handle,
 	/* check if file will be removed due to package upgrade */
 	for(i = handle->trans->add; i; i = i->next) {
 		alpm_pkg_t *spkg = i->data;
-		alpm_pkg_t *pkg = alpm_db_get_pkg(handle->db_local, spkg->name);
+		alpm_pkg_t *pkg = spkg->oldpkg;
 		if(pkg) {
 			alpm_filelist_t filelist = pkg->files;
 			size_t f;
@@ -463,7 +463,7 @@ static int _alpm_hook_trigger_match_pkg(alpm_handle_t *handle,
 		for(i = handle->trans->add; i; i = i->next) {
 			alpm_pkg_t *pkg = i->data;
 			if(_alpm_fnmatch_patterns(t->targets, pkg->name) == 0) {
-				if(alpm_db_get_pkg(handle->db_local, pkg->name)) {
+				if(pkg->oldpkg) {
 					if(t->op & ALPM_HOOK_OP_UPGRADE) {
 						if(hook->needs_targets) {
 							upgrade = alpm_list_add(upgrade, pkg->name);

lib/libalpm/package.c

@@ -682,6 +682,7 @@ void _alpm_pkg_free(alpm_pkg_t *pkg)
 	alpm_list_free(pkg->deltas);
 	alpm_list_free(pkg->delta_path);
 	alpm_list_free(pkg->removes);
+	_alpm_pkg_free(pkg->oldpkg);
 
 	if(pkg->origin == ALPM_PKG_FROM_FILE) {
 		FREE(pkg->origin_data.file);
@@ -707,6 +708,8 @@ void _alpm_pkg_free_trans(alpm_pkg_t *pkg)
 
 	alpm_list_free(pkg->removes);
 	pkg->removes = NULL;
+	_alpm_pkg_free(pkg->oldpkg);
+	pkg->oldpkg = NULL;
 }
 
 /* Is spkg an upgrade for localpkg? */

lib/libalpm/package.h

@@ -117,6 +117,7 @@ struct __alpm_pkg_t {
 	alpm_list_t *deltas;
 	alpm_list_t *delta_path;
 	alpm_list_t *removes; /* in transaction targets only */
+	alpm_pkg_t *oldpkg; /* in transaction targets only */
 
 	struct pkg_operations *ops;
 

lib/libalpm/sync.c

@@ -659,10 +659,15 @@ int _alpm_sync_prepare(alpm_handle_t *handle, alpm_list_t **data)
 	for(i = trans->add; i; i = i->next) {
 		/* update download size field */
 		alpm_pkg_t *spkg = i->data;
+		alpm_pkg_t *lpkg = alpm_db_get_pkg(handle->db_local, spkg->name);
 		if(compute_download_size(spkg) < 0) {
 			ret = -1;
 			goto cleanup;
 		}
+		if(lpkg && _alpm_pkg_dup(lpkg, &spkg->oldpkg) != 0) {
+			ret = -1;
+			goto cleanup;
+		}
 	}
 
 cleanup:
@@ -1260,6 +1265,9 @@ static int load_packages(alpm_handle_t *handle, alpm_list_t **data,
 		pkgfile->reason = spkg->reason;
 		/* copy over validation method */
 		pkgfile->validation = spkg->validation;
+		/* transfer oldpkg */
+		pkgfile->oldpkg = spkg->oldpkg;
+		spkg->oldpkg = NULL;
 		i->data = pkgfile;
 		/* spkg has been removed from the target list, so we can free the
 		 * sync-specific fields */

test/pacman/tests/TESTS

@@ -59,6 +59,7 @@ TESTS += test/pacman/tests/hook-file-remove-trigger-match.py
 TESTS += test/pacman/tests/hook-file-upgrade-nomatch.py
 TESTS += test/pacman/tests/hook-invalid-trigger.py
 TESTS += test/pacman/tests/hook-pkg-install-trigger-match.py
+TESTS += test/pacman/tests/hook-pkg-postinstall-trigger-match.py
 TESTS += test/pacman/tests/hook-pkg-remove-trigger-match.py
 TESTS += test/pacman/tests/hook-pkg-upgrade-trigger-match.py
 TESTS += test/pacman/tests/hook-target-list.py

test/pacman/tests/hook-pkg-postinstall-trigger-match.py

@@ -0,0 +1,23 @@
+self.description = "Install a package matching a PostTransaction Install hook"
+
+self.add_script("hook-script", ": > hook-output")
+self.add_hook("hook",
+        """
+        [Trigger]
+        Type = Package
+        Operation = Install
+        Target = foo
+
+        [Action]
+        When = PostTransaction
+        Exec = bin/hook-script
+        """);
+
+sp = pmpkg("foo")
+self.addpkg2db("sync", sp)
+
+self.args = "-S foo"
+
+self.addrule("PACMAN_RETCODE=0")
+self.addrule("PKG_EXIST=foo")
+self.addrule("FILE_EXIST=hook-output")