[pacman-dev] [PATCH v2] conflict: skip dir children when replacing a file

[Andrew Gregory]

When replacing a file with a directory, any files under that directory
do not need to be checked for conflicts.  This prevents possible
false-positive conflicts where the file being replaced is a symlink.

We were already skipping the directory children when the file was owned
by the previous version of a package being upgraded.  This extends that
to other packages being removed.

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

v2: include the test file

 lib/libalpm/conflict.c                        | 16 +++++++++++++++-
 test/pacman/tests/TESTS                       |  1 +
 test/pacman/tests/symlink-replace-with-dir.py | 18 ++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 test/pacman/tests/symlink-replace-with-dir.py

diff --git a/lib/libalpm/conflict.c b/lib/libalpm/conflict.c
index b9e30870..48bc88b6 100644
--- a/lib/libalpm/conflict.c
+++ b/lib/libalpm/conflict.c
@@ -503,6 +503,7 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 			struct stat lsbuf;
 			char path[PATH_MAX];
 			size_t pathlen;
+			int pfile_isdir;
 
 			pathlen = snprintf(path, PATH_MAX, "%s%s", handle->root, filestr);
 			relative_path = path + rootlen;
@@ -514,7 +515,8 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 
 			_alpm_log(handle, ALPM_LOG_DEBUG, "checking possible conflict: %s\n", path);
 
-			if(path[pathlen - 1] == '/') {
+			pfile_isdir = path[pathlen - 1] == '/';
+			if(pfile_isdir) {
 				if(S_ISDIR(lsbuf.st_mode)) {
 					_alpm_log(handle, ALPM_LOG_DEBUG, "file is a directory, not a conflict\n");
 					continue;
@@ -551,6 +553,18 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 					_alpm_log(handle, ALPM_LOG_DEBUG,
 							"local file will be removed, not a conflict\n");
 					resolved_conflict = 1;
+					if(pfile_isdir) {
+						/* go ahead and skip any files inside filestr as they will
+						 * necessarily be resolved by replacing the file with a dir
+						 * NOTE: afterward, j will point to the last file inside filestr */
+						size_t fslen = strlen(filestr);
+						for( ; j->next; j = j->next) {
+							const char *filestr2 = j->next->data;
+							if(strncmp(filestr, filestr2, fslen) != 0) {
+								break;
+							}
+						}
+					}
 				}
 			}
 
diff --git a/test/pacman/tests/TESTS b/test/pacman/tests/TESTS
index 2d877962..44007f63 100644
--- a/test/pacman/tests/TESTS
+++ b/test/pacman/tests/TESTS
@@ -149,6 +149,7 @@ TESTS += test/pacman/tests/smoke001.py
 TESTS += test/pacman/tests/smoke002.py
 TESTS += test/pacman/tests/smoke003.py
 TESTS += test/pacman/tests/smoke004.py
+TESTS += test/pacman/tests/symlink-replace-with-dir.py
 TESTS += test/pacman/tests/symlink001.py
 TESTS += test/pacman/tests/symlink002.py
 TESTS += test/pacman/tests/symlink010.py
diff --git a/test/pacman/tests/symlink-replace-with-dir.py b/test/pacman/tests/symlink-replace-with-dir.py
new file mode 100644
index 00000000..511d751b
--- /dev/null
+++ b/test/pacman/tests/symlink-replace-with-dir.py
@@ -0,0 +1,18 @@
+self.description = "incoming package replaces symlink with directory"
+
+lp = pmpkg("pkg1")
+lp.files = ["usr/lib/foo",
+            "lib -> usr/lib"]
+self.addpkg2db("local", lp)
+
+p1 = pmpkg("pkg2")
+p1.files = ["lib/foo"]
+p1.conflicts = ["pkg1"]
+self.addpkg2db("sync", p1)
+
+self.args = "-S pkg2 --ask=4"
+
+self.addrule("PACMAN_RETCODE=0")
+self.addrule("!PKG_EXIST=pkg1")
+self.addrule("PKG_EXIST=pkg2")
+self.addrule("FILE_TYPE=lib|dir")
-- 
2.11.0