From: Andrew Fyfe <andrew@neptune-one.net>
Date: Sun, 8 Jul 2007 00:02:48 +0000 (+0100)
Subject: FS#7484 - pacman clobbers directory symlinks.
X-Git-Url: http://lithium.sol/gitweb/?p=pacman;a=commitdiff_plain;h=c992a5d757efa5aee45ed4cc48e02218be933101

FS#7484 - pacman clobbers directory symlinks.

If a file/directory/symlink does not already exist on the filesystem,
then it is extracted as normal.

When extracting a directory:
- If a directory or symlink already exists on the filesystem then the
  directory is not extracted.

When extracting a symlink:
- If a directory already exists on the filesystem then the symlink is
  not extracted.

When extracting a special file (FIFO, block dev or char dev):
- If the file it is replacing is a special file no backup checks are
  done.

For all other cases when a file exists on the filesystem the normal
backuup checks are performed.

Signed-off-by: Andrew Fyfe <andrew@neptune-one.net>
---

diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
index 870d1f8..62bc2f7 100644
--- a/lib/libalpm/add.c
+++ b/lib/libalpm/add.c
@@ -439,6 +439,7 @@ int _alpm_add_commit(pmtrans_t *trans, pmdb_t *db)
 				int needbackup = 0, notouch = 0;
 				char *hash_orig = NULL;
 				struct stat buf;
+				mode_t entrytype = archive_entry_filetype(entry);
 
 				entryname = archive_entry_pathname(entry);
 
@@ -459,11 +460,7 @@ int _alpm_add_commit(pmtrans_t *trans, pmdb_t *db)
 
 				memset(filename, 0, PATH_MAX); /* just to be sure */
 
-				if(strcmp(entryname, ".PKGINFO") == 0
-						|| strcmp(entryname, ".FILELIST") == 0) {
-					archive_read_data_skip(archive);
-					continue;
-				} else if(strcmp(entryname, ".INSTALL") == 0) {
+				if(strcmp(entryname, ".INSTALL") == 0) {
 					/* the install script goes inside the db */
 					snprintf(filename, PATH_MAX, "%s/%s-%s/install", db->path,
 									 newpkg->name, newpkg->version);
@@ -498,31 +495,56 @@ int _alpm_add_commit(pmtrans_t *trans, pmdb_t *db)
 				}
 
 				/* check is file already exists */
-				if(stat(filename, &buf) == 0 && !S_ISDIR(buf.st_mode)) {
-					/* it does, is it a backup=() file?
-					 * always check the newpkg first, so when we do add a backup=() file,
-					 * we don't have to wait a full upgrade cycle */
-					needbackup = alpm_list_find_str(alpm_pkg_get_backup(newpkg), entryname);
-
-					if(is_upgrade) {
-						hash_orig = _alpm_needbackup(entryname, alpm_pkg_get_backup(oldpkg));
-						if(hash_orig) {
-							needbackup = 1;
-						}
+				if(stat(filename, &buf) == 0) {
+					if ( S_ISDIR(entrytype) && (S_ISDIR(buf.st_mode) || S_ISLNK(buf.st_mode)) ) {
+						/* If the package entry is a directory and there's a directory or
+						 * symlink with the same name on the filesystem, skip this entry. */
+						_alpm_log(PM_LOG_DEBUG, _("%s (directory) won't be extracted over existing directory or symlink"), entryname);
+						archive_read_data_skip(archive);
+						continue;
 					}
 
-					/* this is kind of gross.  if we force hash_orig to be non-NULL we can
-					 * catch the pro-active backup=() case (when the backup entry is in
-					 * the new package, and not the old */
-					if(needbackup && !hash_orig) {
-						hash_orig = strdup("");
+					if ( S_ISLNK(entrytype) && S_ISDIR(buf.st_mode) ) {
+						/* If the package entry is a symlink and the fs entry is a
+						 * directory, skip this entry. */
+						_alpm_log(PM_LOG_DEBUG, _("%s (symlink) won't be extracted over existing directory."), entryname);
+						archive_read_data_skip(archive);
+						continue;
 					}
-					
-					/* NoUpgrade skips all this backup stuff, because it's just never
-					 * touched */
-					if(alpm_list_find_str(handle->noupgrade, entryname)) {
-						notouch = 1;
-						needbackup = 0;
+
+					if ( (S_ISFIFO(entrytype) || S_ISBLK(entrytype) || S_ISCHR(entrytype)) &&
+						(S_ISFIFO(buf.st_mode) || S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode)) ) {
+						/* If the package entry is a FIFO, block device or character device
+						 * and the filesystem entry is a FIFO, block devicce or character device
+						 * unlink the fs entry and extract the package entry. */
+						_alpm_log(PM_LOG_DEBUG, _("%s is a FIFO/block/character device, extracting as normal."), entryname);
+					}
+					else {
+						/* it does, is it a backup=() file?
+						 * always check the newpkg first, so when we do add a backup=() file,
+						 * we don't have to wait a full upgrade cycle */
+						needbackup = alpm_list_find_str(alpm_pkg_get_backup(newpkg), entryname);
+
+						if(is_upgrade) {
+							hash_orig = _alpm_needbackup(entryname, alpm_pkg_get_backup(oldpkg));
+							if(hash_orig) {
+								needbackup = 1;
+							}
+						}
+
+						/* this is kind of gross.  if we force hash_orig to be non-NULL we can
+						 * catch the pro-active backup=() case (when the backup entry is in
+						 * the new package, and not the old */
+						if(needbackup && !hash_orig) {
+							hash_orig = strdup("");
+						}
+
+						/* NoUpgrade skips all this backup stuff, because it's just never
+						 * touched */
+						if(alpm_list_find_str(handle->noupgrade, entryname)) {
+							notouch = 1;
+							needbackup = 0;
+						}
 					}
 				}