Enable seamless compression for WIN32

In the archival code we pretend that WIN32 is a no-MMU platform and
use the new mingw_popen_fd routine to pipe data to/from commands
to compress/decompress.

The pretence is maintained by redefining MMU macros in bb_archive.h.
This is mostly used in the archival code but there are a handful
of places where it's used to access public interfaces.  The symbol
BB_ARCHIVE_PUBLIC is defined in these places.

With these changes:

   tar supports seamless compression/decompression
   rpm2cpio and dpkg-deb can be enabled

1 files changed, 30 insertions, 1 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 85551684b..1f9dd23d2 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -617,6 +617,7 @@ static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statb
 }
 
 #if SEAMLESS_COMPRESSION
+#if !ENABLE_PLATFORM_MINGW32
 /* Don't inline: vfork scares gcc and pessimizes code */
 static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
 {
@@ -676,6 +677,27 @@ static void NOINLINE vfork_compressor(int tar_fd, const char *gzip)
                 bb_perror_msg_and_die("can't execute '%s'", gzip);
         }
 }
+#else
+static pid_t vfork_compressor(int tar_fd, const char *gzip)
+{
+        char *cmd;
+        int fd1;
+        pid_t pid;
+
+        if (find_applet_by_name(gzip) >= 0) {
+                cmd = xasprintf("%s %s -cf -", bb_busybox_exec_path, gzip);
+        }
+        else {
+                cmd = xasprintf("%s -cf -", gzip);
+        }
+        if ( (fd1=mingw_popen_fd(cmd, "w", tar_fd, &pid)) == -1 ) {
+                bb_perror_msg_and_die("can't execute '%s'", gzip);
+        }
+        free(cmd);
+        xmove_fd(fd1, tar_fd);
+        return pid;
+}
+#endif /* ENABLE_PLATFORM_MINGW32 */
 #endif /* SEAMLESS_COMPRESSION */
 
 
@@ -691,6 +713,7 @@ static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 {
         int errorFlag = FALSE;
         struct TarBallInfo tbInfo;
+        IF_PLATFORM_MINGW32(pid_t pid = 0;)
 
         tbInfo.hlInfoHead = NULL;
         tbInfo.tarFd = tar_fd;
@@ -702,7 +725,7 @@ static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 
 #if SEAMLESS_COMPRESSION
         if (gzip)
-                vfork_compressor(tbInfo.tarFd, gzip);
+                IF_PLATFORM_MINGW32(pid = )vfork_compressor(tbInfo.tarFd, gzip);
 #endif
 
         tbInfo.excludeList = exclude;
@@ -738,7 +761,11 @@ static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
 #if SEAMLESS_COMPRESSION
         if (gzip) {
                 int status;
+#if !ENABLE_PLATFORM_MINGW32
                 if (safe_waitpid(-1, &status, 0) == -1)
+#else
+                if (safe_waitpid(pid, &status, 0) == -1)
+#endif
                         bb_perror_msg("waitpid");
                 else if (!WIFEXITED(status) || WEXITSTATUS(status))
                         /* gzip was killed or has exited with nonzero! */
@@ -1208,10 +1235,12 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
         if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
                 close(tar_handle->src_fd);
 
+#if !ENABLE_PLATFORM_MINGW32
         if (SEAMLESS_COMPRESSION || OPT_COMPRESS) {
                 /* Set bb_got_signal to 1 if a child died with !0 exitcode */
                 check_errors_in_children(0);
         }
+#endif
 
         return bb_got_signal;
 }