Slight improvements to tar code, and fix to -e soft.

1 files changed, 16 insertions, 21 deletions

diff --git a/src/is_tar.c b/src/is_tar.c
index f962edbd..876c631b 100644
--- a/src/is_tar.c
+++ b/src/is_tar.c
@@ -2,7 +2,7 @@
  * Copyright (c) Ian F. Darwin 1986-1995.
  * Software written by Ian F. Darwin and others;
  * maintained 1995-present by Christos Zoulas and others.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -12,7 +12,7 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- *  
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@@ -40,7 +40,7 @@
 #include "file.h"
 
 #ifndef lint
-FILE_RCSID("@(#)$File: is_tar.c,v 1.36 2009/02/03 20:27:51 christos Exp $")
+FILE_RCSID("@(#)$File: is_tar.c,v 1.37 2010/11/30 14:58:53 rrt Exp $")
 #endif
 
 #include "magic.h"
@@ -83,8 +83,8 @@ file_is_tar(struct magic_set *ms, const unsigned char *buf, size_t nbytes)
 }
 
 /*
- * Return 
- *	0 if the checksum is bad (i.e., probably not a tar archive), 
+ * Return
+ *	0 if the checksum is bad (i.e., probably not a tar archive),
  *	1 for old UNIX tar file,
  *	2 for Unix Std (POSIX) tar file,
  *	3 for GNU tar file.
@@ -95,7 +95,7 @@ is_tar(const unsigned char *buf, size_t nbytes)
 	const union record *header = (const union record *)(const void *)buf;
 	int	i;
 	int	sum, recsum;
-	const char	*p;
+	const unsigned char	*p;
 
 	if (nbytes < sizeof(union record))
 		return 0;
@@ -104,25 +104,20 @@ is_tar(const unsigned char *buf, size_t nbytes)
 
 	sum = 0;
 	p = header->charptr;
-	for (i = sizeof(union record); --i >= 0;) {
-		/*
-		 * We cannot use unsigned char here because of old compilers,
-		 * e.g. V7.
-		 */
-		sum += 0xFF & *p++;
-	}
+	for (i = sizeof(union record); --i >= 0;)
+		sum += *p++;
 
 	/* Adjust checksum to count the "chksum" field as blanks. */
 	for (i = sizeof(header->header.chksum); --i >= 0;)
-		sum -= 0xFF & header->header.chksum[i];
-	sum += ' '* sizeof header->header.chksum;	
+		sum -= header->header.chksum[i];
+	sum += ' ' * sizeof header->header.chksum;
 
 	if (sum != recsum)
 		return 0;	/* Not a tar archive */
-	
-	if (strcmp(header->header.magic, GNUTMAGIC) == 0) 
+
+	if (strcmp(header->header.magic, GNUTMAGIC) == 0)
 		return 3;		/* GNU Unix Standard tar archive */
-	if (strcmp(header->header.magic, TMAGIC) == 0) 
+	if (strcmp(header->header.magic, TMAGIC) == 0)
 		return 2;		/* Unix Standard tar archive */
 
 	return 1;			/* Old fashioned tar archive */
@@ -132,7 +127,7 @@ is_tar(const unsigned char *buf, size_t nbytes)
 /*
  * Quick and dirty octal conversion.
  *
- * Result is -1 if the field is invalid (all blank, or nonoctal).
+ * Result is -1 if the field is invalid (all blank, or non-octal).
  */
 private int
 from_oct(int digs, const char *where)
@@ -145,13 +140,13 @@ from_oct(int digs, const char *where)
 			return -1;		/* All blank field */
 	}
 	value = 0;
-	while (digs > 0 && isodigit(*where)) {	/* Scan til nonoctal */
+	while (digs > 0 && isodigit(*where)) {	/* Scan til non-octal */
 		value = (value << 3) | (*where++ - '0');
 		--digs;
 	}
 
 	if (digs > 0 && *where && !isspace((unsigned char)*where))
-		return -1;			/* Ended on non-space/nul */
+		return -1;			/* Ended on non-(space/NUL) */
 
 	return value;
 }