bzcat: fix unpacking of more than one file, and unpacking of zero-size bz2. Closes 4393

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

archival/bbunzip.c

@@ -103,6 +103,8 @@ int FAST_FUNC bbunpack(char **argv,
 		status = unpacker(&info);
 		if (status < 0)
 			exitcode = 1;
+
+		if (!(option_mask32 & OPT_STDOUT))
 			xclose(STDOUT_FILENO); /* with error check! */
 
 		if (filename) {
@@ -143,6 +145,9 @@ int FAST_FUNC bbunpack(char **argv,
 		}
 	} while (*argv && *++argv);
 
+	if (option_mask32 & OPT_STDOUT)
+		xclose(STDOUT_FILENO); /* with error check! */
+
 	return exitcode;
 }
 

archival/libarchive/decompress_bunzip2.c

@@ -752,7 +752,14 @@ unpack_bz2_stream(int src_fd, int dst_fd)
 			}
 		}
 
-		if (i != RETVAL_LAST_BLOCK) {
+		if (i != RETVAL_LAST_BLOCK
+		/* Observed case when i == RETVAL_OK:
+		 * "bzcat z.bz2", where "z.bz2" is a bzipped zero-length file
+		 * (to be exact, z.bz2 is exactly these 14 bytes:
+		 * 42 5a 68 39 17 72 45 38  50 90 00 00 00 00).
+		 */
+		 && i != RETVAL_OK
+		) {
 			bb_error_msg("bunzip error %d", i);
 			break;
 		}

testsuite/bzcat.tests

@@ -1,54 +1,28 @@
 #!/bin/sh
+# Copyright 2011 by Denys Vlasenko
+# Licensed under GPLv2, see file LICENSE in this source tree.
 
-FAILCOUNT=0
+. ./testing.sh
 
-ext=bz2
+# testing "test name" "command" "expected result" "file input" "stdin"
 
-bb="busybox "
+# "input" file is bzipped file with "a\n" data
+testing "bzcat can print many files" \
+"$ECHO -ne '$hexdump' | bzcat input input; echo \$?" \
+"\
+a
+a
+0
+" "\
+\x42\x5a\x68\x39\x31\x41\x59\x26\x53\x59\x63\x3e\xd6\xe2\x00\x00\
+\x00\xc1\x00\x00\x10\x20\x00\x20\x00\x21\x00\x82\xb1\x77\x24\x53\
+\x85\x09\x06\x33\xed\x6e\x20\
+" ""
 
-unset LC_ALL
-unset LC_MESSAGES
-unset LANG
-unset LANGUAGE
+# "input" file is bzipped zero byte file
+testing "bzcat can handle compressed zero-length bzip2 files" \
+"$ECHO -ne '$hexdump' | bzcat input input; echo \$?" \
+"0\n" \
+"\x42\x5a\x68\x39\x17\x72\x45\x38\x50\x90\x00\x00\x00\x00" ""
 
-hello_gz() {
-    # Gzipped "HELLO\n"
-    #_________________________ vvv vvv vvv vvv - mtime
-    $ECHO -ne "\x1f\x8b\x08\x00\x85\x1d\xef\x45\x02\x03\xf3\x70\xf5\xf1\xf1\xe7"
-    $ECHO -ne "\x02\x00\x6e\xd7\xac\xfd\x06\x00\x00\x00"
-}
-
-hello_bz2() {
-    # Bzipped "HELLO\n"
-    $ECHO -ne "\x42\x5a\x68\x39\x31\x41\x59\x26\x53\x59\x5b\xb8\xe8\xa3\x00\x00"
-    $ECHO -ne "\x01\x44\x00\x00\x10\x02\x44\xa0\x00\x30\xcd\x00\xc3\x46\x29\x97"
-    $ECHO -ne "\x17\x72\x45\x38\x50\x90\x5b\xb8\xe8\xa3"
-}
-
-prep() {
-    rm -f t*
-    hello_$ext >t1.$ext
-    hello_$ext >t2.$ext
-}
-
-check() {
-    eval $2 >t_actual 2>&1
-    if $ECHO -ne "$expected" | cmp - t_actual; then
-	echo "PASS: $1"
-    else
-	echo "FAIL: $1"
-	FAILCOUNT=$((FAILCOUNT + 1))
-    fi
-}
-
-mkdir testdir 2>/dev/null
-(
-cd testdir || { echo "cannot cd testdir!"; exit 1; }
-
-expected="HELLO\nok\n"
-prep; check "bzcat: dont delete src" "${bb}bzcat t2.bz2; test -f t2.bz2 && echo ok"
-
-)
-rm -rf testdir
-
-exit $((FAILCOUNT <= 255 ? FAILCOUNT : 255))
+exit $FAILCOUNT