Fix for trans001.py (FS#9088)

From now on _alpm_db_find_fileconflicts() works with upgrade and remove
target lists (like checkdeps), which makes it transaction independent
(we still need a trans param because of the progressbar). This is a small
step towards the universal transaction. So we call this function directly
from sync.c before commiting the remove transaction. This is much safer,
but we can get false fileconflict error alarms in some tricky cases
("symlinks puzzle" etc).

The patch on find_fileconflict looks complex, but it is mainly an
"indent-patch", the new code-part can be found after the
/* check remove list ... */ comment, and I modified something around the
"file has changed hand" case (see comment modifications in the code).

Unfortunately sync.c became more ugly, because we have to create 2 parallel
internal transactions: to avoid duplicated work, upgrade transaction is
used to load package data (filelists). This problem will disappear, when
we finally get rid of internal transactions.

Signed-off-by: Nagy Gabor <ngaba@bibl.u-szeged.hu>
Signed-off-by: Dan McGee <dan@archlinux.org>

4 files changed, 112 insertions, 94 deletions

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index 6eb2085e..3c0074f5 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -166,7 +166,7 @@ int _alpm_add_prepare(pmtrans_t *trans, pmdb_t *db, alpm_list_t **data)
 		EVENT(trans, PM_TRANS_EVT_FILECONFLICTS_START, NULL, NULL);
 
 		_alpm_log(PM_LOG_DEBUG, "looking for file conflicts\n");
-		lp = _alpm_db_find_fileconflicts(db, trans, handle->root);
+		lp = _alpm_db_find_fileconflicts(db, trans, trans->packages, NULL);
 		if(lp != NULL) {
 			if(data) {
 				*data = lp;
diff --git a/lib/libalpm/conflict.c b/lib/libalpm/conflict.c
index 499e55a4..4daa2194 100644
--- a/lib/libalpm/conflict.c
+++ b/lib/libalpm/conflict.c
@@ -350,16 +350,16 @@ void _alpm_fileconflict_free(pmfileconflict_t *conflict)
 /* Find file conflicts that may occur during the transaction with two checks:
  * 1: check every target against every target
  * 2: check every target against the filesystem */
-alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *root)
+alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans,
+		alpm_list_t *upgrade, alpm_list_t *remove)
 {
-	alpm_list_t *i, *conflicts = NULL;
-	alpm_list_t *targets = trans->packages;
-	int numtargs = alpm_list_count(targets);
+	alpm_list_t *i, *j, *conflicts = NULL;
+	int numtargs = alpm_list_count(upgrade);
 	int current;
 
 	ALPM_LOG_FUNC;
 
-	if(db == NULL || targets == NULL || root == NULL) {
+	if(db == NULL || upgrade == NULL) {
 		return(NULL);
 	}
 
@@ -367,8 +367,8 @@ alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *roo
 	 * be possible with real transactions. Right now we only do half as much
 	 * here as we do when we actually extract files in add.c with our 12
 	 * different cases. */
-	for(current = 1, i = targets; i; i = i->next, current++) {
-		alpm_list_t *j, *k, *tmpfiles = NULL;
+	for(current = 1, i = upgrade; i; i = i->next, current++) {
+		alpm_list_t *k, *tmpfiles = NULL;
 		pmpkg_t *p1, *p2, *dbpkg;
 		char path[PATH_MAX+1];
 
@@ -392,7 +392,7 @@ alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *roo
 
 			if(tmpfiles) {
 				for(k = tmpfiles; k; k = k->next) {
-					snprintf(path, PATH_MAX, "%s%s", root, (char *)k->data);
+					snprintf(path, PATH_MAX, "%s%s", handle->root, (char *)k->data);
 					conflicts = add_fileconflict(conflicts, PM_FILECONFLICT_TARGET, path,
 							alpm_pkg_get_name(p1), alpm_pkg_get_name(p2));
 				}
@@ -408,7 +408,7 @@ alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *roo
 		_alpm_log(PM_LOG_DEBUG, "searching for filesystem conflicts: %s\n", p1->name);
 		dbpkg = _alpm_db_get_pkgfromcache(db, p1->name);
 
-		/* Do two different checks here. f the package is currently installed,
+		/* Do two different checks here. If the package is currently installed,
 		 * then only check files that are new in the new package. If the package
 		 * is not currently installed, then simply stat the whole filelist */
 		if(dbpkg) {
@@ -420,12 +420,10 @@ alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *roo
 			tmpfiles = alpm_list_strdup(alpm_pkg_get_files(p1));
 		}
 
-		/* loop over each file to be installed */
 		for(j = tmpfiles; j; j = j->next) {
-			int skip_conflict = 0;
 			filestr = j->data;
 
-			snprintf(path, PATH_MAX, "%s%s", root, filestr);
+			snprintf(path, PATH_MAX, "%s%s", handle->root, filestr);
 
 			/* stat the file - if it exists, do some checks */
 			if(_alpm_lstat(path, &lsbuf) != 0) {
@@ -436,48 +434,50 @@ alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *roo
 			if(path[strlen(path)-1] == '/') {
 				if(S_ISDIR(lsbuf.st_mode)) {
 					_alpm_log(PM_LOG_DEBUG, "%s is a directory, not a conflict\n", path);
-					skip_conflict = 1;
+					continue;
 				} else if(S_ISLNK(lsbuf.st_mode) && S_ISDIR(sbuf.st_mode)) {
 					_alpm_log(PM_LOG_DEBUG,
 							"%s is a symlink to a dir, hopefully not a conflict\n", path);
-					skip_conflict = 1;
+					continue;
 				}
 			}
-			if(!skip_conflict) {
-				_alpm_log(PM_LOG_DEBUG, "checking possible conflict: %s\n", path);
-
-				/* Look at all the targets to see if file has changed hands */
-				int resolved_conflict = 0; /* have we acted on this conflict? */
-				for(k = targets; k; k = k->next) {
-					p2 = k->data;
-					if(!p2 || strcmp(p1->name, p2->name) == 0) {
-						continue;
-					}
+			_alpm_log(PM_LOG_DEBUG, "checking possible conflict: %s\n", path);
 
-					pmpkg_t *localp2 = _alpm_db_get_pkgfromcache(db, p2->name);
-
-					/* Check if it used to exist in a package, but doesn't anymore */
-					alpm_list_t *pkgfiles, *localfiles; /* added for readability */
-					pkgfiles = alpm_pkg_get_files(p2);
-					localfiles = alpm_pkg_get_files(localp2);
-
-					if(localp2 && !alpm_list_find_str(pkgfiles, filestr)
-						 && alpm_list_find_str(localfiles, filestr)) {
-						/* skip removal of file, but not add. this will prevent a second
-						 * package from removing the file when it was already installed
-						 * by its new owner (whether the file is in backup array or not */
-						trans->skip_remove = alpm_list_add(trans->skip_remove, strdup(path));
-						_alpm_log(PM_LOG_DEBUG, "file changed packages, adding to remove skiplist: %s\n", filestr);
-						resolved_conflict = 1;
-						break;
-					}
+			int resolved_conflict = 0; /* have we acted on this conflict? */
+
+			/* Check remove list (will we remove the conflicting local file?) */
+			for(k = remove; k && !resolved_conflict; k = k->next) {
+				pmpkg_t *rempkg = k->data;
+				if(rempkg && alpm_list_find_str(alpm_pkg_get_files(rempkg), filestr)) {
+					_alpm_log(PM_LOG_DEBUG, "local file will be removed, not a conflict: %s\n", filestr);
+					resolved_conflict = 1;
 				}
-				if(!resolved_conflict) {
-					_alpm_log(PM_LOG_DEBUG, "file found in conflict: %s\n", path);
-					conflicts = add_fileconflict(conflicts, PM_FILECONFLICT_FILESYSTEM,
-							path, p1->name, NULL);
+			}
+
+			/* Look at all the targets to see if file has changed hands */
+			for(k = upgrade; k && !resolved_conflict; k = k->next) {
+				p2 = k->data;
+				if(!p2 || strcmp(p1->name, p2->name) == 0) {
+					continue;
+				}
+				pmpkg_t *localp2 = _alpm_db_get_pkgfromcache(db, p2->name);
+
+				/* localp2->files will be removed (target conflicts are handled by CHECK 1) */
+				if(localp2 && alpm_list_find_str(alpm_pkg_get_files(localp2), filestr)) {
+					/* skip removal of file, but not add. this will prevent a second
+					 * package from removing the file when it was already installed
+					 * by its new owner (whether the file is in backup array or not */
+					trans->skip_remove = alpm_list_add(trans->skip_remove, strdup(path));
+					_alpm_log(PM_LOG_DEBUG, "file changed packages, adding to remove skiplist: %s\n", filestr);
+					resolved_conflict = 1;
 				}
 			}
+
+			if(!resolved_conflict) {
+				_alpm_log(PM_LOG_DEBUG, "file found in conflict: %s\n", path);
+				conflicts = add_fileconflict(conflicts, PM_FILECONFLICT_FILESYSTEM,
+						path, p1->name, NULL);
+			}
 		}
 		FREELIST(tmpfiles);
 	}
diff --git a/lib/libalpm/conflict.h b/lib/libalpm/conflict.h
index 71ed579d..1c673728 100644
--- a/lib/libalpm/conflict.h
+++ b/lib/libalpm/conflict.h
@@ -41,7 +41,8 @@ void _alpm_conflict_free(pmconflict_t *conflict);
 int _alpm_conflict_isin(pmconflict_t *needle, alpm_list_t *haystack);
 alpm_list_t *_alpm_innerconflicts(alpm_list_t *packages);
 alpm_list_t *_alpm_outerconflicts(pmdb_t *db, alpm_list_t *packages);
-alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans, char *root);
+alpm_list_t *_alpm_db_find_fileconflicts(pmdb_t *db, pmtrans_t *trans,
+					 alpm_list_t *upgrade, alpm_list_t *remove);
 
 void _alpm_fileconflict_free(pmfileconflict_t *conflict);
 
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index e5a5f7ed..e1ab1c92 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -818,7 +818,7 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 {
 	alpm_list_t *i, *j, *files = NULL;
 	alpm_list_t *deltas = NULL;
-	pmtrans_t *tr = NULL;
+	pmtrans_t *tr_remove = NULL, *tr_upgrade = NULL;
 	int replaces = 0;
 	int errors = 0;
 	const char *cachedir = NULL;
@@ -962,61 +962,44 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 		return(0);
 	}
 
-	/* remove conflicting and to-be-replaced packages */
 	trans->state = STATE_COMMITING;
-	tr = _alpm_trans_new();
-	if(tr == NULL) {
+
+	/* Create remove and upgrade transactions */
+	tr_remove = _alpm_trans_new();
+	if(tr_remove == NULL) {
 		_alpm_log(PM_LOG_ERROR, _("could not create removal transaction\n"));
 		goto error;
 	}
+	tr_upgrade = _alpm_trans_new();
+	if(tr_upgrade == NULL) {
+		_alpm_log(PM_LOG_ERROR, _("could not create transaction\n"));
+		goto error;
+	}
 
-	if(_alpm_trans_init(tr, PM_TRANS_TYPE_REMOVE, PM_TRANS_FLAG_NODEPS, NULL, NULL, NULL) == -1) {
+	if(_alpm_trans_init(tr_remove, PM_TRANS_TYPE_REMOVE, PM_TRANS_FLAG_NODEPS, NULL, NULL, NULL) == -1) {
 		_alpm_log(PM_LOG_ERROR, _("could not initialize the removal transaction\n"));
 		goto error;
 	}
+	if(_alpm_trans_init(tr_upgrade, PM_TRANS_TYPE_UPGRADE, trans->flags, trans->cb_event, trans->cb_conv, trans->cb_progress) == -1) {
+		_alpm_log(PM_LOG_ERROR, _("could not initialize transaction\n"));
+		goto error;
+	}
 
+	/* adding targets */
 	for(i = trans->packages; i; i = i->next) {
 		pmsyncpkg_t *sync = i->data;
 		alpm_list_t *j;
+		/* remove transaction */
 		for(j = sync->removes; j; j = j->next) {
 			pmpkg_t *pkg = j->data;
-			if(!_alpm_pkg_find(tr->packages, pkg->name)) {
-				if(_alpm_trans_addtarget(tr, pkg->name) == -1) {
+			if(!_alpm_pkg_find(tr_remove->packages, pkg->name)) {
+				if(_alpm_trans_addtarget(tr_remove, pkg->name) == -1) {
 					goto error;
 				}
 				replaces++;
 			}
 		}
-	}
-	if(replaces) {
-		_alpm_log(PM_LOG_DEBUG, "removing conflicting and to-be-replaced packages\n");
-		if(_alpm_trans_prepare(tr, data) == -1) {
-			_alpm_log(PM_LOG_ERROR, _("could not prepare removal transaction\n"));
-			goto error;
-		}
-		/* we want the frontend to be aware of commit details */
-		tr->cb_event = trans->cb_event;
-		if(_alpm_trans_commit(tr, NULL) == -1) {
-			_alpm_log(PM_LOG_ERROR, _("could not commit removal transaction\n"));
-			goto error;
-		}
-	}
-	_alpm_trans_free(tr);
-	tr = NULL;
-
-	/* install targets */
-	_alpm_log(PM_LOG_DEBUG, "installing packages\n");
-	tr = _alpm_trans_new();
-	if(tr == NULL) {
-		_alpm_log(PM_LOG_ERROR, _("could not create transaction\n"));
-		goto error;
-	}
-	if(_alpm_trans_init(tr, PM_TRANS_TYPE_UPGRADE, trans->flags | PM_TRANS_FLAG_NODEPS, trans->cb_event, trans->cb_conv, trans->cb_progress) == -1) {
-		_alpm_log(PM_LOG_ERROR, _("could not initialize transaction\n"));
-		goto error;
-	}
-	for(i = trans->packages; i; i = i->next) {
-		pmsyncpkg_t *sync = i->data;
+		/* upgrade transaction */
 		pmpkg_t *spkg = sync->pkg;
 		const char *fname;
 		char *fpath;
@@ -1028,7 +1011,7 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 		/* Loop through the cache dirs until we find a matching file */
 		fpath = _alpm_filecache_find(fname);
 
-		if(_alpm_trans_addtarget(tr, fpath) == -1) {
+		if(_alpm_trans_addtarget(tr_upgrade, fpath) == -1) {
 			FREE(fpath);
 			goto error;
 		}
@@ -1036,15 +1019,50 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 
 		/* using alpm_list_last() is ok because addtarget() adds the new target at the
 		 * end of the tr->packages list */
-		spkg = alpm_list_last(tr->packages)->data;
+		spkg = alpm_list_last(tr_upgrade->packages)->data;
 		spkg->reason = sync->newreason;
 	}
-	if(_alpm_trans_prepare(tr, data) == -1) {
-		_alpm_log(PM_LOG_ERROR, _("could not prepare transaction\n"));
-		/* pm_errno is set by trans_prepare */
-		goto error;
+
+	/* fileconflict check */
+	if(!(trans->flags & PM_TRANS_FLAG_FORCE)) {
+		EVENT(trans, PM_TRANS_EVT_FILECONFLICTS_START, NULL, NULL);
+
+		_alpm_log(PM_LOG_DEBUG, "looking for file conflicts\n");
+		alpm_list_t *conflict = _alpm_db_find_fileconflicts(db_local, tr_upgrade,
+								    tr_upgrade->packages, tr_remove->packages);
+		if(conflict) {
+			pm_errno = PM_ERR_FILE_CONFLICTS;
+			if(data) {
+				*data = conflict;
+			} else {
+				alpm_list_free_inner(conflict, (alpm_list_fn_free)_alpm_fileconflict_free);
+				alpm_list_free(conflict);
+			}
+			goto error;
+		}
+
+		EVENT(trans, PM_TRANS_EVT_FILECONFLICTS_DONE, NULL, NULL);
 	}
-	if(_alpm_trans_commit(tr, NULL) == -1) {
+
+	/* remove conflicting and to-be-replaced packages */
+	if(replaces) {
+		_alpm_log(PM_LOG_DEBUG, "removing conflicting and to-be-replaced packages\n");
+		if(_alpm_trans_prepare(tr_remove, data) == -1) {
+			_alpm_log(PM_LOG_ERROR, _("could not prepare removal transaction\n"));
+			goto error;
+		}
+		/* we want the frontend to be aware of commit details */
+		tr_remove->cb_event = trans->cb_event;
+		if(_alpm_trans_commit(tr_remove, NULL) == -1) {
+			_alpm_log(PM_LOG_ERROR, _("could not commit removal transaction\n"));
+			goto error;
+		}
+	}
+
+	/* install targets */
+	_alpm_log(PM_LOG_DEBUG, "installing packages\n");
+	/* add_prepare is not needed */
+	if(_alpm_trans_commit(tr_upgrade, NULL) == -1) {
 		_alpm_log(PM_LOG_ERROR, _("could not commit transaction\n"));
 		goto error;
 	}
@@ -1053,9 +1071,8 @@ int _alpm_sync_commit(pmtrans_t *trans, pmdb_t *db_local, alpm_list_t **data)
 error:
 	FREELIST(files);
 	alpm_list_free(deltas);
-	deltas = NULL;
-	_alpm_trans_free(tr);
-	tr = NULL;
+	_alpm_trans_free(tr_remove);
+	_alpm_trans_free(tr_upgrade);
 	return(ret);
 }