[src/trunk]: src/usr.bin/unzip Switch to the less restrictive binary detectio...

[joerg <joerg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/28936f0cfb8d
branches:  trunk
changeset: 754373:28936f0cfb8d
user:      joerg <joerg%NetBSD.org@localhost>
date:      Thu Apr 29 06:32:19 2010 +0000

description:
Switch to the less restrictive binary detection algorithm from zip 3.0e.

diffstat:

 usr.bin/unzip/unzip.c |  44 +++++++++++++++++++++++++++++++++++---------
 1 files changed, 35 insertions(+), 9 deletions(-)

diffs (81 lines):

diff -r 3d2b310f16e4 -r 28936f0cfb8d usr.bin/unzip/unzip.c
--- a/usr.bin/unzip/unzip.c     Thu Apr 29 06:07:35 2010 +0000
+++ b/usr.bin/unzip/unzip.c     Thu Apr 29 06:32:19 2010 +0000
@@ -1,7 +1,7 @@
-/* $NetBSD: unzip.c,v 1.12 2010/02/18 15:51:57 joerg Exp $ */
+/* $NetBSD: unzip.c,v 1.13 2010/04/29 06:32:19 joerg Exp $ */
 
 /*-
- * Copyright (c) 2009 Joerg Sonnenberger <joerg%NetBSD.org@localhost>
+ * Copyright (c) 2009, 2010 Joerg Sonnenberger <joerg%NetBSD.org@localhost>
  * Copyright (c) 2007-2008 Dag-Erling Coïdan Smørgrav
  * All rights reserved.
  *
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: unzip.c,v 1.12 2010/02/18 15:51:57 joerg Exp $");
+__RCSID("$NetBSD: unzip.c,v 1.13 2010/04/29 06:32:19 joerg Exp $");
 
 #include <sys/queue.h>
 #include <sys/stat.h>
@@ -459,6 +459,34 @@
 }
 
 /*
+ * Detect binary files by a combination of character white list and
+ * black list. NUL bytes and other control codes without use in text files
+ * result directly in switching the file to binary mode. Otherwise, at least
+ * one white-listed byte has to be found.
+ *
+ * Black-listed: 0..6, 14..25, 28..31
+ * White-listed: 9..10, 13, >= 32
+ *
+ * See the proginfo/txtvsbin.txt in the zip sources for a detailed discussion.
+ */
+#define BYTE_IS_BINARY(x)      ((x) < 32 && (0xf3ffc07fU & (1U << (x))))
+#define        BYTE_IS_TEXT(x)         ((x) >= 32 || (0x00002600U & (1U << (x))))
+
+static int
+check_binary(const unsigned char *buf, size_t len)
+{
+       int rv;
+       for (rv = 1; len--; ++buf) {
+               if (BYTE_IS_BINARY(*buf))
+                       return 1;
+               if (BYTE_IS_TEXT(*buf))
+                       rv = 0;
+       }
+
+       return rv;
+}
+
+/*
  * Extract a regular file.
  */
 static void
@@ -544,11 +572,9 @@
                 * guess wrong, we print a warning message later.
                 */
                if (a_opt && n == 0) {
-                       for (p = buffer; p < end; ++p) {
-                               if (!isascii((unsigned char)*p)) {
-                                       text = 0;
-                                       break;
-                               }
+                       if (check_binary(buffer, len)) {
+                               text = 0;
+                               break;
                        }
                }
 
@@ -562,7 +588,7 @@
                /* hard case: convert \r\n to \n (sigh...) */
                for (p = buffer; p < end; p = q + 1) {
                        for (q = p; q < end; q++) {
-                               if (!warn && !isascii(*q)) {
+                               if (!warn && BYTE_IS_BINARY(*q)) {
                                        warningx("%s may be corrupted due"
                                            " to weak text file detection"
                                            " heuristic", *path);