rpm: code shrink. Now uses open_zipped's logic (factored out into setup_unzip_on_fd())

function                                             old     new   delta
setup_unzip_on_fd                                      -      80     +80
open_zipped                                          176     113     -63
rpm_main                                            1672    1355    -317
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 80/-380)          Total: -300 bytes

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

1 files changed, 55 insertions, 42 deletions

diff --git a/libbb/read.c b/libbb/read.c
index 06ce297..503216e 100644
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -6,7 +6,6 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
-
 #include "libbb.h"
 
 #define ZIPPED (ENABLE_FEATURE_SEAMLESS_LZMA \
@@ -16,7 +15,7 @@
 )
 
 #if ZIPPED
-#include "unarchive.h"
+# include "unarchive.h"
 #endif
 
 ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
@@ -306,14 +305,11 @@ void* FAST_FUNC xmalloc_xopen_read_close(const char *filename, size_t *maxsz_p)
 	return buf;
 }
 
-int FAST_FUNC open_zipped(const char *fname)
+#if ZIPPED
+int FAST_FUNC setup_unzip_on_fd(int fd /*, int fail_if_not_detected*/)
 {
-#if !ZIPPED
-	return open(fname, O_RDONLY);
-#else
+	const int fail_if_not_detected = 1;
 	unsigned char magic[2];
-	char *sfx;
-	int fd;
 #if BB_MMU
 	IF_DESKTOP(long long) int FAST_FUNC (*xformer)(int src_fd, int dst_fd);
 	enum { xformer_prog = 0 };
@@ -322,6 +318,56 @@ int FAST_FUNC open_zipped(const char *fname)
 	const char *xformer_prog;
 #endif
 
+	/* .gz and .bz2 both have 2-byte signature, and their
+	 * unpack_XXX_stream wants this header skipped. */
+	xread(fd, &magic, 2);
+#if ENABLE_FEATURE_SEAMLESS_GZ
+# if BB_MMU
+	xformer = unpack_gz_stream;
+# else
+	xformer_prog = "gunzip";
+# endif
+#endif
+	if (!ENABLE_FEATURE_SEAMLESS_GZ
+	 || magic[0] != 0x1f || magic[1] != 0x8b
+	) {
+		if (!ENABLE_FEATURE_SEAMLESS_BZ2
+		 || magic[0] != 'B' || magic[1] != 'Z'
+		) {
+			if (fail_if_not_detected)
+				bb_error_msg_and_die("no gzip"
+					IF_FEATURE_SEAMLESS_BZ2("/bzip2")
+					" magic");
+			xlseek(fd, -2, SEEK_CUR);
+			return fd;
+		}
+#if BB_MMU
+		xformer = unpack_bz2_stream;
+#else
+		xformer_prog = "bunzip2";
+#endif
+	} else {
+#if !BB_MMU
+		/* NOMMU version of open_transformer execs
+		 * an external unzipper that wants
+		 * file position at the start of the file */
+		xlseek(fd, -2, SEEK_CUR);
+#endif
+	}
+	open_transformer(fd, xformer, xformer_prog);
+
+	return fd;
+}
+#endif /* ZIPPED */
+
+int FAST_FUNC open_zipped(const char *fname)
+{
+#if !ZIPPED
+	return open(fname, O_RDONLY);
+#else
+	char *sfx;
+	int fd;
+
 	fd = open(fname, O_RDONLY);
 	if (fd < 0)
 		return fd;
@@ -335,40 +381,7 @@ int FAST_FUNC open_zipped(const char *fname)
 		if ((ENABLE_FEATURE_SEAMLESS_GZ && strcmp(sfx, ".gz") == 0)
 		 || (ENABLE_FEATURE_SEAMLESS_BZ2 && strcmp(sfx, ".bz2") == 0)
 		) {
-			/* .gz and .bz2 both have 2-byte signature, and their
-			 * unpack_XXX_stream wants this header skipped. */
-			xread(fd, &magic, 2);
-#if ENABLE_FEATURE_SEAMLESS_GZ
-#if BB_MMU
-			xformer = unpack_gz_stream;
-#else
-			xformer_prog = "gunzip";
-#endif
-#endif
-			if (!ENABLE_FEATURE_SEAMLESS_GZ
-			 || magic[0] != 0x1f || magic[1] != 0x8b
-			) {
-				if (!ENABLE_FEATURE_SEAMLESS_BZ2
-				 || magic[0] != 'B' || magic[1] != 'Z'
-				) {
-					bb_error_msg_and_die("no gzip"
-						IF_FEATURE_SEAMLESS_BZ2("/bzip2")
-						" magic");
-				}
-#if BB_MMU
-				xformer = unpack_bz2_stream;
-#else
-				xformer_prog = "bunzip2";
-#endif
-			} else {
-#if !BB_MMU
-				/* NOMMU version of open_transformer execs
-				 * an external unzipper that wants
-				 * file position at the start of the file */
-				xlseek(fd, 0, SEEK_SET);
-#endif
-			}
-			open_transformer(fd, xformer, xformer_prog);
+			setup_unzip_on_fd(fd /*, fail_if_not_detected: 1*/);
 		}
 	}