From: Brian Weaver <cmdrclueless@gmail.com>
Date: Wed, 26 Sep 2012 15:45:52 +0000 (-0400)
Subject: Refactored common code into a single function
X-Git-Tag: v3.1.0~41^2~1^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F26%2Fhead;p=thirdparty%2Flibarchive.git

Refactored common code into a single function

The tar_atol8() and tar_atol10() functions were essentially
identical. The code has been refactored to a common function
with tar_atol8() and tar_atol10() calling the commont function
with the radix instead duplicating the code.

The logic was also changed slightly to prevent a pointer
dereference when a zero length character array is passed to
the conversion routine.
---

diff --git a/libarchive/archive_read_support_format_tar.c b/libarchive/archive_read_support_format_tar.c
index ed5799333..8f5059767 100644
--- a/libarchive/archive_read_support_format_tar.c
+++ b/libarchive/archive_read_support_format_tar.c
@@ -2407,16 +2407,18 @@ tar_atol(const char *p, unsigned char_cnt)
  * it does obey locale.
  */
 static int64_t
-tar_atol8(const char *p, unsigned char_cnt)
+tar_atol_base_n(const char *p, unsigned char_cnt, int base)
 {
 	int64_t	l, limit, last_digit_limit;
-	int digit, sign, base;
+	int digit, sign;
 
-	base = 8;
 	limit = INT64_MAX / base;
 	last_digit_limit = INT64_MAX % base;
 
-	while ((*p == ' ' || *p == '\t') && char_cnt != 0) {
+	/* the pointer will not be dereferenced if char_cnt is zero
+	 * due to the way the && operator is evaulated.
+	 */
+	while (char_cnt != 0 && (*p == ' ' || *p == '\t')) {
 		p++;
 		char_cnt--;
 	}
@@ -2444,47 +2446,16 @@ tar_atol8(const char *p, unsigned char_cnt)
 	return (sign < 0) ? -l : l;
 }
 
-/*
- * Note that this implementation does not (and should not!) obey
- * locale settings; you cannot simply substitute strtol here, since
- * it does obey locale.
- */
 static int64_t
-tar_atol10(const char *p, unsigned char_cnt)
+tar_atol8(const char *p, unsigned char_cnt)
 {
-	int64_t l, limit, last_digit_limit;
-	int base, digit, sign;
-
-	base = 10;
-	limit = INT64_MAX / base;
-	last_digit_limit = INT64_MAX % base;
-
-	while ((*p == ' ' || *p == '\t') && char_cnt != 0) {
-		p++;
-		char_cnt--;
-	}
-
-	sign = 1;
-	if (char_cnt != 0 && *p == '-') {
-		sign = -1;
-		p++;
-		char_cnt--;
-	}
+	return tar_atol_base_n(p, char_cnt, 8);
+}
 
-	l = 0;
-	if (char_cnt != 0) {
-		digit = *p - '0';
-		while (digit >= 0 && digit < base  && char_cnt != 0) {
-			if (l > limit || (l == limit && digit > last_digit_limit)) {
-				l = INT64_MAX; /* Truncate on overflow. */
-				break;
-			}
-			l = (l * base) + digit;
-			digit = *++p - '0';
-			char_cnt--;
-		}
-	}
-	return (sign < 0) ? -l : l;
+static int64_t
+tar_atol10(const char *p, unsigned char_cnt)
+{
+	return tar_atol_base_n(p, char_cnt, 10);
 }
 
 /*