skip conflicts resolved by file replacement

When replacing a file with a directory, any files inside the new
directory cannot possibly exist on the filesystem and can be skipped.
This allows cross-package symlink-to-directory transitions when there
are files with the same name under both the symlinked directory and the
new directory.

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

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/libalpm/conflict.c b/lib/libalpm/conflict.c
index 41b8393c..a70023b1 100644
--- a/lib/libalpm/conflict.c
+++ b/lib/libalpm/conflict.c
@@ -566,6 +566,8 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 
 				/* localp2->files will be removed (target conflicts are handled by CHECK 1) */
 				if(localp2 && alpm_filelist_contains(alpm_pkg_get_files(localp2), relative_path)) {
+					size_t fslen = strlen(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 */
@@ -574,6 +576,19 @@ alpm_list_t *_alpm_db_find_fileconflicts(alpm_handle_t *handle,
 					_alpm_log(handle, ALPM_LOG_DEBUG,
 							"file changed packages, adding to remove skiplist\n");
 					resolved_conflict = 1;
+
+					if(filestr[fslen - 1] == '/') {
+						/* replacing a file with a directory:
+						 * 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 */
+						for( ; j->next; j = j->next) {
+							const char *filestr2 = j->next->data;
+							if(strncmp(filestr, filestr2, fslen) != 0) {
+								break;
+							}
+						}
+					}
 				}
 			}