tar: shrink hardlink name handling code

function                                             old     new   delta
data_extract_all                                    1069    1040     -29

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

1 files changed, 17 insertions, 26 deletions

diff --git a/archival/libarchive/data_extract_all.c b/archival/libarchive/data_extract_all.c
index bd51d2ad3..cf821c9de 100644
--- a/archival/libarchive/data_extract_all.c
+++ b/archival/libarchive/data_extract_all.c
@@ -12,12 +12,11 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
         file_header_t *file_header = archive_handle->file_header;
         int dst_fd;
         int res;
+        char *hard_link;
 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
         char *dst_name;
-        char *dst_link;
 #else
 # define dst_name (file_header->name)
-# define dst_link (file_header->link_target)
 #endif
 
 #if ENABLE_FEATURE_TAR_SELINUX
@@ -31,9 +30,14 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
         }
 #endif
 
+        /* Hard links are encoded as regular files of size 0
+         * with a nonempty link field */
+        hard_link = NULL;
+        if (S_ISREG(file_header->mode) && file_header->size == 0)
+                hard_link = file_header->link_target;
+
 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
         dst_name = file_header->name;
-        dst_link = file_header->link_target;
         if (archive_handle->tar__strip_components) {
                 unsigned n = archive_handle->tar__strip_components;
                 do {
@@ -47,21 +51,18 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
                          * Link target is shortened only for hardlinks:
                          * softlinks restored unchanged.
                          */
-                        if (S_ISREG(file_header->mode)
-                         && file_header->size == 0
-                         && dst_link
-                        ) {
+                        if (hard_link) {
 // GNU tar 1.26 does not check that we reached end of link name:
 // if "dir/hardlink" is hardlinked to "file",
 // tar xvf a.tar --strip-components=1 says:
 //  tar: hardlink: Cannot hard link to '': No such file or directory
 // and continues processing. We silently skip such entries.
-                                dst_link = strchr(dst_link, '/');
-                                if (!dst_link || dst_link[1] == '\0') {
+                                hard_link = strchr(hard_link, '/');
+                                if (!hard_link || hard_link[1] == '\0') {
                                         data_skip(archive_handle);
                                         return;
                                 }
-                                dst_link++;
+                                hard_link++;
                         }
                 } while (--n != 0);
         }
@@ -79,12 +80,7 @@ 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)) {
-                        /* Is it hardlink?
-                         * We encode hard links as regular files of size 0 with a symlink */
-                        if (S_ISREG(file_header->mode)
-                         && file_header->size == 0
-                         && dst_link
-                        ) {
+                        if (hard_link) {
                                 /* Ugly special case:
                                  * tar cf t.tar hardlink1 hardlink2 hardlink1
                                  * results in this tarball structure:
@@ -92,7 +88,7 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
                                  * hardlink2 -> hardlink1
                                  * hardlink1 -> hardlink1 <== !!!
                                  */
-                                if (strcmp(dst_link, dst_name) == 0)
+                                if (strcmp(hard_link, dst_name) == 0)
                                         goto ret;
                         }
                         /* Proceed with deleting */
@@ -128,19 +124,14 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
                 }
         }
 
-        /* Handle hard links separately
-         * We encode hard links as regular files of size 0 with a symlink */
-        if (S_ISREG(file_header->mode)
-         && file_header->size == 0
-         && dst_link
-        ) {
-                /* Hard link */
-                res = link(dst_link, dst_name);
+        /* Handle hard links separately */
+        if (hard_link) {
+                res = link(hard_link, dst_name);
                 if (res != 0 && !(archive_handle->ah_flags & ARCHIVE_EXTRACT_QUIET)) {
                         bb_perror_msg("can't create %slink "
                                         "from %s to %s", "hard",
                                         dst_name,
-                                        dst_link);
+                                        hard_link);
                 }
                 /* Hardlinks have no separate mode/ownership, skip chown/chmod */
                 goto ret;