From 5355d387e90c8e74ca4c7b9d2e2f7eb828a08ea3 Mon Sep 17 00:00:00 2001
From: Jason King <jason.brian.king@gmail.com>
Date: Thu, 7 Sep 2017 17:21:14 +0000
Subject: [PATCH] Use strtoll to parse ints

---
 json_util.c | 123 ++++------------------------------------------------
 1 file changed, 8 insertions(+), 115 deletions(-)

diff --git a/json_util.c b/json_util.c
index 4624668..00cdc30 100644
--- a/json_util.c
+++ b/json_util.c
@@ -57,10 +57,6 @@
 #include "json_tokener.h"
 #include "json_util.h"
 
-static int sscanf_is_broken = 0;
-static int sscanf_is_broken_testdone = 0;
-static void sscanf_is_broken_test(void);
-
 static int _json_object_to_fd(int fd, struct json_object *obj, int flags, const char *filename);
 
 static char _last_err[256] = "";
@@ -195,119 +191,16 @@ int json_parse_double(const char *buf, double *retval)
   return end == buf ? 1 : 0;
 }
 
-/*
- * Not all implementations of sscanf actually work properly.
- * Check whether the one we're currently using does, and if
- * it's broken, enable the workaround code.
- */
-static void sscanf_is_broken_test()
-{
-	int64_t num64;
-	int ret_errno, is_int64_min, ret_errno2, is_int64_max;
-
-	(void)sscanf(" -01234567890123456789012345", "%" SCNd64, &num64);
-	ret_errno = errno;
-	is_int64_min = (num64 == INT64_MIN);
-
-	(void)sscanf(" 01234567890123456789012345", "%" SCNd64, &num64);
-	ret_errno2 = errno;
-	is_int64_max = (num64 == INT64_MAX);
-
-	if (ret_errno != ERANGE || !is_int64_min ||
-	    ret_errno2 != ERANGE || !is_int64_max)
-	{
-		MC_DEBUG("sscanf_is_broken_test failed, enabling workaround code\n");
-		sscanf_is_broken = 1;
-	}
-}
-
 int json_parse_int64(const char *buf, int64_t *retval)
 {
-	int64_t num64;
-	const char *buf_sig_digits;
-	int orig_has_neg;
-	int saved_errno;
-
-	if (!sscanf_is_broken_testdone)
-	{
-		sscanf_is_broken_test();
-		sscanf_is_broken_testdone = 1;
-	}
-
-	// Skip leading spaces
-	while (isspace((int)*buf) && *buf)
-		buf++;
-
-	errno = 0; // sscanf won't always set errno, so initialize
-	if (sscanf(buf, "%" SCNd64, &num64) != 1)
-	{
-		MC_DEBUG("Failed to parse, sscanf != 1\n");
-		return 1;
-	}
-
-	saved_errno = errno;
-	buf_sig_digits = buf;
-	orig_has_neg = 0;
-	if (*buf_sig_digits == '-')
-	{
-		buf_sig_digits++;
-		orig_has_neg = 1;
-	}
-
-	// Not all sscanf implementations actually work
-	if (sscanf_is_broken && saved_errno != ERANGE)
-	{
-		char buf_cmp[100];
-		char *buf_cmp_start = buf_cmp;
-		int recheck_has_neg = 0;
-		int buf_cmp_len;
-
-		// Skip leading zeros, but keep at least one digit
-		while (buf_sig_digits[0] == '0' && buf_sig_digits[1] != '\0')
-			buf_sig_digits++;
-		// Can't check num64==0 because some sscanf impl's parse
-		//  non-zero values to 0.  (e.g. Illumos with UINT64_MAX)
-		if (buf_sig_digits[0] == '0' && buf_sig_digits[1] == '\0')
-			orig_has_neg = 0; // "-0" is the same as just plain "0"
-
-		snprintf(buf_cmp_start, sizeof(buf_cmp), "%" PRId64, num64);
-		if (*buf_cmp_start == '-')
-		{
-			recheck_has_neg = 1;
-			buf_cmp_start++;
-		}
-		// No need to skip leading spaces or zeros here.
-
-		buf_cmp_len = strlen(buf_cmp_start);
-		/**
-		 * If the sign is different, or
-		 * some of the digits are different, or
-		 * there is another digit present in the original string
-		 * then we have NOT successfully parsed the value.
-		 */
-		if (orig_has_neg != recheck_has_neg ||
-		    strncmp(buf_sig_digits, buf_cmp_start, strlen(buf_cmp_start)) != 0 ||
-			((int)strlen(buf_sig_digits) != buf_cmp_len &&
-			 isdigit((int)buf_sig_digits[buf_cmp_len])
-		    )
-		   )
-		{
-			saved_errno = ERANGE;
-		}
-	}
-
-	// Not all sscanf impl's set the value properly when out of range.
-	// Always do this, even for properly functioning implementations,
-	// since it shouldn't slow things down much.
-	if (saved_errno == ERANGE)
-	{
-		if (orig_has_neg)
-			num64 = INT64_MIN;
-		else
-			num64 = INT64_MAX;
-	}
-	*retval = num64;
-	return 0;
+	char *end = NULL;
+	int64_t val;
+
+	errno = 0;
+	val = strtoll(buf, &end, 10);
+	if (end != buf)
+		*retval = val;
+	return ((val == 0 && errno != 0) || (end == buf)) ? 1 : 0;
 }
 
 #ifndef HAVE_REALLOC