dpkg: fix handling of names with leading dots. Closes bug 783

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/archival/dpkg.c b/archival/dpkg.c
index 616bce977..9f58b54e6 100644
--- a/archival/dpkg.c
+++ b/archival/dpkg.c
@@ -1493,7 +1493,18 @@ static void FAST_FUNC data_extract_all_prefix(archive_handle_t *archive_handle)
 {
         char *name_ptr = archive_handle->file_header->name;
 
-        name_ptr += strspn(name_ptr, "./");
+        /* Skip all leading "/" */
+        while (*name_ptr == '/')
+                name_ptr++;
+        /* Skip all leading "./" and "../" */
+        while (name_ptr[0] == '.') {
+                if (name_ptr[1] == '.' && name_ptr[2] == '/')
+                        name_ptr++;
+                if (name_ptr[1] != '/')
+                        break;
+                name_ptr += 2;
+        }
+
         if (name_ptr[0] != '\0') {
                 archive_handle->file_header->name = xasprintf("%s%s", archive_handle->dpkg__buffer, name_ptr);
                 data_extract_all(archive_handle);