From 02365a6ef73defb8689d3ed5228125d72993dec9 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 9 Apr 2010 10:52:52 +0200 Subject: tar: fix mishandling of repeated hardlink in tarball; expand tests function old new delta data_extract_all 727 767 +40 get_header_tar 1576 1572 -4 Signed-off-by: Denys Vlasenko --- archival/libunarchive/data_extract_all.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) (limited to 'archival/libunarchive/data_extract_all.c') diff --git a/archival/libunarchive/data_extract_all.c b/archival/libunarchive/data_extract_all.c index cc4894229..de2367ac2 100644 --- a/archival/libunarchive/data_extract_all.c +++ b/archival/libunarchive/data_extract_all.c @@ -34,12 +34,30 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) if (archive_handle->ah_flags & ARCHIVE_UNLINK_OLD) { /* Remove the entry if it exists */ - if ((!S_ISDIR(file_header->mode)) - && (unlink(file_header->name) == -1) - && (errno != ENOENT) - ) { - bb_perror_msg_and_die("can't remove old file %s", - file_header->name); + if (!S_ISDIR(file_header->mode)) { + /* Is it hardlink? + * We encode hard links as regular files of size 0 with a symlink */ + if (S_ISREG(file_header->mode) + && file_header->link_target + && file_header->size == 0 + ) { + /* Ugly special case: + * tar cf t.tar hardlink1 hardlink2 hardlink1 + * results in this tarball structure: + * hardlink1 + * hardlink2 -> hardlink1 + * hardlink1 -> hardlink1 <== !!! + */ + if (strcmp(file_header->link_target, file_header->name) == 0) + goto ret; + } + /* Proceed with deleting */ + if (unlink(file_header->name) == -1 + && errno != ENOENT + ) { + bb_perror_msg_and_die("can't remove old file %s", + file_header->name); + } } } else if (archive_handle->ah_flags & ARCHIVE_EXTRACT_NEWER) { @@ -65,7 +83,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle) } /* Handle hard links separately - * We identified hard links as regular files of size 0 with a symlink */ + * We encode hard links as regular files of size 0 with a symlink */ if (S_ISREG(file_header->mode) && file_header->link_target && file_header->size == 0 -- cgit v1.2.3