add --preremove option

Allows adding and removing packages within a single transaction. This is
particularly useful for complicated conflicts that ALPM cannot resolve
on its own, e.g.:

https://archlinux.org/news/linux-firmware-2025061312fe085f-5-upgrade-requires-manual-intervention/

Currently, dealing with these situations requires doing something
complicated like bypassing dependency checking to break and then repair
the database in two separate steps. By allowing installation and removal
within a single transaction no bypass is required:

 pacman -Syu --preremove linux-firmware linux-firmware

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>

doc/pacman.8.asciidoc

@@ -292,6 +292,9 @@ Upgrade Options (apply to '-S' and '-U')[[UO]]
 	exclamation mark. Subsequent matches will override previous ones. A leading
 	literal exclamation mark or backslash needs to be escaped.
 
+*\--preremove <package>::
+	Uninstall 'package' before performing the requested installation. Multiple
+	packages can be specified by separating them with commas.
 
 Query Options (apply to '-Q')[[QO]]
 -----------------------------------

lib/libalpm/alpm.h

@@ -242,8 +242,6 @@ typedef enum _alpm_errno_t {
 	ALPM_ERR_DB_INVALID,
 	/** Database has an invalid signature */
 	ALPM_ERR_DB_INVALID_SIG,
-	/** Database is signed by an invalid key */
-	ALPM_ERR_DB_INVALID_KEY,
 	/** The localdb is in a newer/older format than libalpm expects */
 	ALPM_ERR_DB_VERSION,
 	/** Failed to write to the database */
@@ -287,8 +285,6 @@ typedef enum _alpm_errno_t {
 	ALPM_ERR_PKG_INVALID_CHECKSUM,
 	/** Package has an invalid signature */
 	ALPM_ERR_PKG_INVALID_SIG,
-	/** Package is signed by an invalid key */
-	ALPM_ERR_PKG_INVALID_KEY,
 	/** Package does not have a signature */
 	ALPM_ERR_PKG_MISSING_SIG,
 	/** Cannot open the package file */
@@ -304,8 +300,6 @@ typedef enum _alpm_errno_t {
 	ALPM_ERR_SIG_MISSING,
 	/** Signatures are invalid */
 	ALPM_ERR_SIG_INVALID,
-	/** Keys are missing from keyring */
-	ALPM_ERR_KEY_MISSING,
 	/* Dependencies */
 	/** Dependencies could not be satisfied */
 	ALPM_ERR_UNSATISFIED_DEPS,

lib/libalpm/be_package.c

@@ -341,17 +341,15 @@ int _alpm_pkg_validate_internal(alpm_handle_t *handle,
 	/* even if we don't have a sig, run the check code if level tells us to */
 	if(level & ALPM_SIG_PACKAGE) {
 		const char *sig = syncpkg ? syncpkg->base64_sig : NULL;
-		int ret;
 		_alpm_log(handle, ALPM_LOG_DEBUG, "sig data: %s\n", sig ? sig : "<from .sig>");
 		if(!has_sig && !(level & ALPM_SIG_PACKAGE_OPTIONAL)) {
 			handle->pm_errno = ALPM_ERR_PKG_MISSING_SIG;
 			return -1;
 		}
-		ret = _alpm_check_pgp_helper(handle, pkgfile, sig,
+		if(_alpm_check_pgp_helper(handle, pkgfile, sig,
 					level & ALPM_SIG_PACKAGE_OPTIONAL, level & ALPM_SIG_PACKAGE_MARGINAL_OK,
-					level & ALPM_SIG_PACKAGE_UNKNOWN_OK, sigdata);
-		if(ret) {
-			handle->pm_errno = ret == -1 ? ALPM_ERR_PKG_INVALID_SIG : ALPM_ERR_PKG_INVALID_KEY;
+					level & ALPM_SIG_PACKAGE_UNKNOWN_OK, sigdata)) {
+			handle->pm_errno = ALPM_ERR_PKG_INVALID_SIG;
 			return -1;
 		}
 		if(validation && has_sig) {
@@ -768,7 +766,6 @@ int SYMEXPORT alpm_pkg_load(alpm_handle_t *handle, const char *filename, int ful
 
 			if(fail) {
 				_alpm_log(handle, ALPM_LOG_ERROR, _("required key missing from keyring\n"));
-				handle->pm_errno = ALPM_ERR_KEY_MISSING;
 				free(sigpath);
 				return -1;
 			}

lib/libalpm/be_sync.c

@@ -126,7 +126,6 @@ static int sync_db_validate(alpm_db_t *db)
 			db->status &= ~DB_STATUS_VALID;
 			db->status |= DB_STATUS_INVALID;
 			db->handle->pm_errno = ALPM_ERR_DB_INVALID_SIG;
-			db->handle->pm_errno = ret == -1 ? ALPM_ERR_PKG_INVALID_SIG : ALPM_ERR_PKG_INVALID_KEY;
 			return 1;
 		}
 	}

lib/libalpm/dload.c

@@ -1118,34 +1118,31 @@ static int finalize_download_locations(alpm_list_t *payloads, const char *localp
 			filename = payload->tempfile_name;
 		}
 
-		if(filename) {
-			int ret = move_file(filename, localpath);
+		/* if neither file exists then the download failed and logged an error for us */
+		if(!filename) {
+			returnvalue = -1;
+			continue;
+		}
 
-			if(ret == -1) {
-				if(payload->mtime_existing_file == 0) {
-					_alpm_log(payload->handle, ALPM_LOG_ERROR, _("could not move %s into %s (%s)\n"),
-							filename, localpath, strerror(errno));
-					returnvalue = -1;
-				}
+		int ret = move_file(filename, localpath);
+
+		if(ret == -1) {
+			/* ignore error if the file already existed - only signature file was downloaded */
+			if(payload->mtime_existing_file == 0) {
+				_alpm_log(payload->handle, ALPM_LOG_ERROR, _("could not move %s into %s (%s)\n"),
+						filename, localpath, strerror(errno));
+				returnvalue = -1;
 			}
 		}
 
 		if (payload->download_signature) {
-			char *sig_filename;
-			int ret;
-
-			filename = payload->destfile_name ? payload->destfile_name : payload->tempfile_name;
-			sig_filename = _alpm_get_fullpath("", filename, ".sig");
-			ASSERT(sig_filename, RET_ERR(payload->handle, ALPM_ERR_MEMORY, -1));
-			ret = move_file(sig_filename, localpath);
-			free(sig_filename);
-
-			if(ret == -1) {
-				sig_filename = _alpm_get_fullpath("", filename, ".sig.part");
-				ASSERT(sig_filename, RET_ERR(payload->handle, ALPM_ERR_MEMORY, -1));
-				move_file(sig_filename, localpath);
-				free(sig_filename);
-			}
+			const char sig_suffix[] = ".sig";
+			char *sig_filename = NULL;
+			size_t sig_filename_len = strlen(filename) + sizeof(sig_suffix);
+			MALLOC(sig_filename, sig_filename_len, continue);
+			snprintf(sig_filename, sig_filename_len, "%s%s", filename, sig_suffix);
+			move_file(sig_filename, localpath);
+			FREE(sig_filename);
 		}
 	}
 	return returnvalue;
@@ -1299,7 +1296,7 @@ download_signature:
 	return ret;
 }
 
-static const char *url_basename(const char *url)
+static char *filecache_find_url(alpm_handle_t *handle, const char *url)
 {
 	const char *filebase = strrchr(url, '/');
 
@@ -1312,7 +1309,7 @@ static const char *url_basename(const char *url)
 		return NULL;
 	}
 
-	return filebase;
+	return _alpm_filecache_find(handle, filebase);
 }
 
 int SYMEXPORT alpm_fetch_pkgurl(alpm_handle_t *handle, const alpm_list_t *urls,
@@ -1334,26 +1331,9 @@ int SYMEXPORT alpm_fetch_pkgurl(alpm_handle_t *handle, const alpm_list_t *urls,
 
 	for(i = urls; i; i = i->next) {
 		char *url = i->data;
-		char *filepath = NULL;
-		const char *urlbase = url_basename(url);
-
-		if(urlbase) {
-			/* attempt to find the file in our pkgcache */
-			filepath = _alpm_filecache_find(handle, urlbase);
-
-			if(filepath && (handle->siglevel & ALPM_SIG_PACKAGE)) {
-				char *sig_filename = _alpm_get_fullpath("", urlbase, ".sig");
-
-				/* if there's no .sig file then forget about the pkg file and go for download */
-				if(!_alpm_filecache_exists(handle, sig_filename)) {
-					free(filepath);
-					filepath = NULL;
-				}
-
-				free(sig_filename);
-			}
-		}
 
+		/* attempt to find the file in our pkgcache */
+		char *filepath = filecache_find_url(handle, url);
 		if(filepath) {
 			/* the file is locally cached so add it to the output right away */
 			alpm_list_append(fetched, filepath);

lib/libalpm/error.c

@@ -72,8 +72,6 @@ const char SYMEXPORT *alpm_strerror(alpm_errno_t err)
 			return _("invalid or corrupted database");
 		case ALPM_ERR_DB_INVALID_SIG:
 			return _("invalid or corrupted database (PGP signature)");
-		case ALPM_ERR_DB_INVALID_KEY:
-			return _("database signature has missing or invalid PGP key");
 		case ALPM_ERR_DB_VERSION:
 			return _("database is incorrect version");
 		case ALPM_ERR_DB_WRITE:
@@ -117,8 +115,6 @@ const char SYMEXPORT *alpm_strerror(alpm_errno_t err)
 			return _("invalid or corrupted package (checksum)");
 		case ALPM_ERR_PKG_INVALID_SIG:
 			return _("invalid or corrupted package (PGP signature)");
-		case ALPM_ERR_PKG_INVALID_KEY:
-			return _("package signature has missing or invalid PGP key");
 		case ALPM_ERR_PKG_MISSING_SIG:
 			return _("package missing required signature");
 		case ALPM_ERR_PKG_OPEN:
@@ -134,8 +130,6 @@ const char SYMEXPORT *alpm_strerror(alpm_errno_t err)
 			return _("missing PGP signature");
 		case ALPM_ERR_SIG_INVALID:
 			return _("invalid PGP signature");
-		case ALPM_ERR_KEY_MISSING:
-			return _("PGP key missing from keyring");
 		/* Dependencies */
 		case ALPM_ERR_UNSATISFIED_DEPS:
 			return _("could not satisfy dependencies");

lib/libalpm/signing.c

@@ -233,14 +233,9 @@ int _alpm_key_in_keychain(alpm_handle_t *handle, const char *fpr)
 		_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup failed, unknown key\n");
 		ret = 0;
 	} else if(gpg_err_code(gpg_err) == GPG_ERR_NO_ERROR) {
-		if(key->expired) {
-			_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup success, but key is expired\n");
-			ret = 0;
-		} else {
-			_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup success, key exists\n");
-			handle->known_keys = alpm_list_add(handle->known_keys, strdup(fpr));
-			ret = 1;
-		}
+		_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup success, key exists\n");
+		handle->known_keys = alpm_list_add(handle->known_keys, strdup(fpr));
+		ret = 1;
 	} else {
 		_alpm_log(handle, ALPM_LOG_DEBUG, "gpg error: %s\n", gpgme_strerror(gpg_err));
 	}
@@ -273,7 +268,7 @@ static int key_import_wkd(alpm_handle_t *handle, const char *email, const char *
 	CHECK_ERR();
 
 	mode = gpgme_get_keylist_mode(ctx);
-	mode |= GPGME_KEYLIST_MODE_LOCATE_EXTERNAL;
+	mode |= GPGME_KEYLIST_MODE_LOCATE;
 	gpg_err = gpgme_set_keylist_mode(ctx, mode);
 	CHECK_ERR();
 
@@ -284,7 +279,7 @@ static int key_import_wkd(alpm_handle_t *handle, const char *email, const char *
 		if(fpr && _alpm_key_in_keychain(handle, fpr)) {
 			ret = 0;
 		} else {
-			_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup failed: WKD imported wrong fingerprint or key expired\n");
+			_alpm_log(handle, ALPM_LOG_DEBUG, "key lookup failed: WKD imported wrong fingerprint\n");
 		}
 	}
 	gpgme_key_unref(key);
@@ -376,7 +371,6 @@ static int key_search_keyserver(alpm_handle_t *handle, const char *fpr,
 	pgpkey->expires = key->subkeys->expires;
 	pgpkey->length = key->subkeys->length;
 	pgpkey->revoked = key->subkeys->revoked;
-	ret = 1;
 
 gpg_error:
 	if(ret != 1) {
@@ -798,7 +792,7 @@ char *_alpm_sigpath(alpm_handle_t *handle, const char *path)
  * @param marginal whether signatures with marginal trust are acceptable
  * @param unknown whether signatures with unknown trust are acceptable
  * @param sigdata a pointer to storage for signature results
- * @return 0 on success, -1 on error, -2 on key error (consult pm_errno or sigdata)
+ * @return 0 on success, -1 on error (consult pm_errno or sigdata)
  */
 int _alpm_check_pgp_helper(alpm_handle_t *handle, const char *path,
 		const char *base64_sig, int optional, int marginal, int unknown,
@@ -806,7 +800,6 @@ int _alpm_check_pgp_helper(alpm_handle_t *handle, const char *path,
 {
 	alpm_siglist_t *siglist;
 	int ret;
-	int key_invalid = 0;
 
 	CALLOC(siglist, 1, sizeof(alpm_siglist_t),
 			RET_ERR(handle, ALPM_ERR_MEMORY, -1));
@@ -828,11 +821,8 @@ int _alpm_check_pgp_helper(alpm_handle_t *handle, const char *path,
 		size_t num;
 		for(num = 0; !ret && num < siglist->count; num++) {
 			switch(siglist->results[num].status) {
-				case ALPM_SIGSTATUS_KEY_EXPIRED:
-					_alpm_log(handle, ALPM_LOG_DEBUG, "key is expired\n");
-					key_invalid = 1;
-					__attribute__((fallthrough));
 				case ALPM_SIGSTATUS_VALID:
+				case ALPM_SIGSTATUS_KEY_EXPIRED:
 					_alpm_log(handle, ALPM_LOG_DEBUG, "signature is valid\n");
 					switch(siglist->results[num].validity) {
 						case ALPM_SIGVALIDITY_FULL:
@@ -856,12 +846,9 @@ int _alpm_check_pgp_helper(alpm_handle_t *handle, const char *path,
 							break;
 					}
 					break;
+				case ALPM_SIGSTATUS_SIG_EXPIRED:
 				case ALPM_SIGSTATUS_KEY_UNKNOWN:
 				case ALPM_SIGSTATUS_KEY_DISABLED:
-				case ALPM_SIGSTATUS_SIG_EXPIRED:
-					_alpm_log(handle, ALPM_LOG_DEBUG, "key is not valid\n");
-					key_invalid = 1;
-					__attribute__((fallthrough));
 				case ALPM_SIGSTATUS_INVALID:
 					_alpm_log(handle, ALPM_LOG_DEBUG, "signature is not valid\n");
 					ret = -1;
@@ -877,7 +864,7 @@ int _alpm_check_pgp_helper(alpm_handle_t *handle, const char *path,
 		free(siglist);
 	}
 
-	return key_invalid ? -2 : ret;
+	return ret;
 }
 
 /**
@@ -910,6 +897,7 @@ int _alpm_process_siglist(alpm_handle_t *handle, const char *identifier,
 		const char *name = result->key.uid ? result->key.uid : result->key.fingerprint;
 		switch(result->status) {
 			case ALPM_SIGSTATUS_VALID:
+			case ALPM_SIGSTATUS_KEY_EXPIRED:
 				switch(result->validity) {
 					case ALPM_SIGVALIDITY_FULL:
 						break;
@@ -935,16 +923,6 @@ int _alpm_process_siglist(alpm_handle_t *handle, const char *identifier,
 								identifier, name);
 						break;
 				}
-				break;
-			case ALPM_SIGSTATUS_KEY_EXPIRED:
-				_alpm_log(handle, ALPM_LOG_ERROR,
-						_("%s: key \"%s\" (%s) is expired\n"),
-						identifier, name, result->key.fingerprint);
-
-				if(_alpm_key_import(handle, result->key.uid, result->key.fingerprint) == 0) {
-					retry = 1;
-				}
-
 				break;
 			case ALPM_SIGSTATUS_KEY_UNKNOWN:
 				/* ensure this key is still actually unknown; we may have imported it

lib/libalpm/sync.c

@@ -975,7 +975,6 @@ static int check_keyring(alpm_handle_t *handle)
 		EVENT(handle, &event);
 		if(fail) {
 			_alpm_log(handle, ALPM_LOG_ERROR, _("required key missing from keyring\n"));
-			handle->pm_errno = ALPM_ERR_KEY_MISSING;
 			return -1;
 		}
 	}
@@ -1054,7 +1053,6 @@ static int check_validity(alpm_handle_t *handle,
 							_("%s: missing required signature\n"), v->pkg->name);
 					break;
 				case ALPM_ERR_PKG_INVALID_SIG:
-				case ALPM_ERR_PKG_INVALID_KEY:
 					_alpm_process_siglist(handle, v->pkg->name, v->siglist,
 							v->siglevel & ALPM_SIG_PACKAGE_OPTIONAL,
 							v->siglevel & ALPM_SIG_PACKAGE_MARGINAL_OK,

src/pacman/callback.c

@@ -529,17 +529,10 @@ void cb_question(void *ctx, alpm_question_t *question)
 		case ALPM_QUESTION_CORRUPTED_PKG:
 			{
 				alpm_question_corrupted_t *q = &question->corrupted;
-				if(q->reason == ALPM_ERR_PKG_INVALID_KEY || q->reason == ALPM_ERR_DB_INVALID_KEY) {
-					q->remove = yesno(_("Can't get PGP key for file %s (%s)\n"
-								"Do you want to delete it?"),
-							q->filepath,
-							alpm_strerror(q->reason));
-				} else {
-					q->remove = yesno(_("File %s is corrupted (%s).\n"
-								"Do you want to delete it?"),
-							q->filepath,
-							alpm_strerror(q->reason));
-				}
+				q->remove = yesno(_("File %s is corrupted (%s).\n"
+							"Do you want to delete it?"),
+						q->filepath,
+						alpm_strerror(q->reason));
 			}
 			break;
 		case ALPM_QUESTION_IMPORT_KEY:

src/pacman/conf.c

@@ -150,6 +150,7 @@ int config_free(config_t *oldconfig)
 	FREELIST(oldconfig->noupgrade);
 	FREELIST(oldconfig->noextract);
 	FREELIST(oldconfig->overwrite_files);
+	FREELIST(oldconfig->preremove);
 	free(oldconfig->configfile);
 	free(oldconfig->sysroot);
 	free(oldconfig->rootdir);

src/pacman/conf.h

@@ -134,6 +134,8 @@ typedef struct __config_t {
 	/* our connection to libalpm */
 	alpm_handle_t *handle;
 
+	alpm_list_t *preremove;
+
 	alpm_list_t *explicit_adds;
 	alpm_list_t *explicit_removes;
 
@@ -214,7 +216,8 @@ enum {
 	OP_REFRESH,
 	OP_ASSUMEINSTALLED,
 	OP_DISABLEDLTIMEOUT,
-	OP_DISABLESANDBOX
+	OP_DISABLESANDBOX,
+	OP_PREREMOVE,
 };
 
 /* clean method */

src/pacman/pacman.c

@@ -196,6 +196,8 @@ static void usage(int op, const char * const myname)
 				addlist(_("      --ignore <pkg>   ignore a package upgrade (can be used more than once)\n"));
 				addlist(_("      --ignoregroup <grp>\n"
 				          "                       ignore a group upgrade (can be used more than once)\n"));
+				addlist(_("      --preremove <pkg>\n"));
+				addlist(_("                       uninstall <pkg> before performing installation\n"));
 				__attribute__((fallthrough));
 			case PM_OP_REMOVE:
 				addlist(_("  -d, --nodeps         skip dependency version checks (-dd to skip all checks)\n"));
@@ -770,6 +772,9 @@ static int parsearg_upgrade(int opt)
 		case OP_IGNOREGROUP:
 			parsearg_util_addlist(&(config->ignoregrp));
 			break;
+		case OP_PREREMOVE:
+			parsearg_util_addlist(&(config->preremove));
+			break;
 		case OP_DOWNLOADONLY:
 		case 'w':
 			config->op_s_downloadonly = 1;
@@ -982,6 +987,7 @@ static int parseargs(int argc, char *argv[])
 		{"color",      required_argument, 0, OP_COLOR},
 		{"disable-download-timeout", no_argument, 0, OP_DISABLEDLTIMEOUT},
 		{"disable-sandbox", no_argument, 0, OP_DISABLESANDBOX},
+		{"preremove", required_argument, 0, OP_PREREMOVE},
 		{0, 0, 0, 0}
 	};
 

src/pacman/sync.c

@@ -717,6 +717,21 @@ static int sync_trans(alpm_list_t *targets)
 		}
 	}
 
+	for(i = config->preremove; i; i = i->next) {
+		alpm_pkg_t *pkg;
+		const char *pname = i->data;
+		alpm_db_t *db_local = alpm_get_localdb(config->handle);
+
+		if((pkg = alpm_db_get_pkg(db_local, pname)) != NULL) {
+			if(alpm_remove_pkg(config->handle, pkg) == -1) {
+				alpm_errno_t err = alpm_errno(config->handle);
+				pm_printf(ALPM_LOG_ERROR, "'%s': %s\n", pname, alpm_strerror(err));
+				retval = 1;
+			}
+			config->explicit_removes = alpm_list_add(config->explicit_removes, pkg);
+		}
+	}
+
 	if(retval) {
 		trans_release();
 		return retval;