Merge r585,r669 from libarchive.googlecode.com: If zlib is unavailable,

use external "gunzip" instead.  With this in place, we can unconditionally
enable gzip read support.

2 files changed, 8 insertions, 7 deletions

diff --git a/lib/libarchive/archive_read_support_compression_all.c b/lib/libarchive/archive_read_support_compression_all.c
index 967546d..745f1ff 100644
--- a/lib/libarchive/archive_read_support_compression_all.c
+++ b/lib/libarchive/archive_read_support_compression_all.c
@@ -36,9 +36,8 @@ archive_read_support_compression_all(struct archive *a)
 #endif
 	/* The decompress code doesn't use an outside library. */
 	archive_read_support_compression_compress(a);
-#if HAVE_ZLIB_H
+	/* Gzip decompress falls back to "gunzip" command-line. */
 	archive_read_support_compression_gzip(a);
-#endif
 #if HAVE_LZMADEC_H
 	/* LZMA bidding is subject to false positives because
 	 * the LZMA file format has a very weak signature.  It
diff --git a/lib/libarchive/archive_read_support_compression_gzip.c b/lib/libarchive/archive_read_support_compression_gzip.c
index 9d06bf6..bc3f143 100644
--- a/lib/libarchive/archive_read_support_compression_gzip.c
+++ b/lib/libarchive/archive_read_support_compression_gzip.c
@@ -91,7 +91,7 @@ archive_read_support_compression_gzip(struct archive *_a)
 	bidder->bid = gzip_bidder_bid;
 	bidder->init = gzip_bidder_init;
 	bidder->options = NULL;
-	bidder->free = NULL;
+	bidder->free = NULL; /* No data, so no cleanup necessary. */
 	return (ARCHIVE_OK);
 }
 
@@ -212,12 +212,14 @@ gzip_bidder_bid(struct archive_read_filter_bidder *self,
  * and emit a useful message.
  */
 static int
-gzip_bidder_init(struct archive_read_filter *filter)
+gzip_bidder_init(struct archive_read_filter *self)
 {
+	int r;
 
-	archive_set_error(&filter->archive->archive, -1,
-	    "This version of libarchive was compiled without gzip support");
-	return (ARCHIVE_FATAL);
+	r = __archive_read_program(self, "gunzip");
+	self->code = ARCHIVE_COMPRESSION_GZIP;
+	self->name = "gzip";
+	return (r);
 }
 
 #else