rpm: use "create+rename" method of replacing existing files

Users were reporting getting errors like
"ls: error while loading shared libraries: libc.so.6: ELF load command past end of file"
while rpm was unpacking glibc tarball.

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

3 files changed, 19 insertions, 3 deletions

diff --git a/archival/libarchive/data_extract_all.c b/archival/libarchive/data_extract_all.c
index 3f67b835f..45776dcbe 100644
--- a/archival/libarchive/data_extract_all.c
+++ b/archival/libarchive/data_extract_all.c
@@ -106,15 +106,28 @@ void FAST_FUNC data_extract_all(archive_handle_t *archive_handle)
         switch (file_header->mode & S_IFMT) {
         case S_IFREG: {
                 /* Regular file */
+                char *dst_name;
                 int flags = O_WRONLY | O_CREAT | O_EXCL;
                 if (archive_handle->ah_flags & ARCHIVE_O_TRUNC)
                         flags = O_WRONLY | O_CREAT | O_TRUNC;
-                dst_fd = xopen3(file_header->name,
+                dst_name = file_header->name;
+#ifdef ARCHIVE_REPLACE_VIA_RENAME
+                if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME)
+                        /* rpm-style temp file name */
+                        dst_name = xasprintf("%s;%x", dst_name, (int)getpid());
+#endif
+                dst_fd = xopen3(dst_name,
                         flags,
                         file_header->mode
                         );
                 bb_copyfd_exact_size(archive_handle->src_fd, dst_fd, file_header->size);
                 close(dst_fd);
+#ifdef ARCHIVE_REPLACE_VIA_RENAME
+                if (archive_handle->ah_flags & ARCHIVE_REPLACE_VIA_RENAME) {
+                        xrename(dst_name, file_header->name);
+                        free(dst_name);
+                }
+#endif
                 break;
         }
         case S_IFDIR:
diff --git a/archival/rpm.c b/archival/rpm.c
index 793701652..6b227d537 100644
--- a/archival/rpm.c
+++ b/archival/rpm.c
@@ -242,8 +242,8 @@ static void extract_cpio(int fd, const char *source_rpm)
                 /* compat: overwrite existing files.
                  * try "rpm -i foo.src.rpm" few times in a row -
                  * standard rpm will not complain.
-                 * (TODO? real rpm creates "file;1234" and then renames it) */
-                | ARCHIVE_UNLINK_OLD;
+                 */
+                | ARCHIVE_REPLACE_VIA_RENAME;
         archive_handle->src_fd = fd;
         /*archive_handle->offset = 0; - init_handle() did it */
 
diff --git a/include/bb_archive.h b/include/bb_archive.h
index a7a2a1135..b82cfd83c 100644
--- a/include/bb_archive.h
+++ b/include/bb_archive.h
@@ -122,6 +122,9 @@ typedef struct archive_handle_t {
 #define ARCHIVE_NUMERIC_OWNER       (1 << 7)
 #define ARCHIVE_O_TRUNC             (1 << 8)
 #define ARCHIVE_REMEMBER_NAMES      (1 << 9)
+#if ENABLE_RPM
+#define ARCHIVE_REPLACE_VIA_RENAME  (1 << 10)
+#endif
 
 
 /* POSIX tar Header Block, from POSIX 1003.1-1990  */