From a870a9f788933a2fcbf5b46e82de0d0684998613 Mon Sep 17 00:00:00 2001
From: pancake <pancake@nopcode.org>
Date: Wed, 8 Jul 2015 18:33:29 +0200
Subject: [PATCH] Refix for #2889 - that was nasty

---
 libr/core/core.c | 9 ++++++---
 libr/util/calc.c | 8 +-------
 libr/util/num.c  | 5 +++--
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/libr/core/core.c b/libr/core/core.c
index dc13b7937028d..c84a45ad2da1e 100644
--- a/libr/core/core.c
+++ b/libr/core/core.c
@@ -146,9 +146,12 @@ static ut64 num_callback(RNum *userptr, const char *str, int *ok) {
 				char *o = strdup (str+1);
 				if (o) {
 					q = r_num_calc_index (core->num, NULL);
-					r_str_replace_char (o, ']', 0);
-					n = r_num_math (core->num, o);
-					r_num_calc_index (core->num, q);
+					if (q) {
+						if (r_str_replace_char (o, ']', 0)>0) {
+							n = r_num_math (core->num, o);
+							r_num_calc_index (core->num, q);
+						}
+					}
 					free (o);
 				}
 			}
diff --git a/libr/util/calc.c b/libr/util/calc.c
index ba63112956344..0078c5863a39d 100644
--- a/libr/util/calc.c
+++ b/libr/util/calc.c
@@ -145,18 +145,12 @@ static void cin_putback (RNum *num, RNumCalc *nc, char c) {
 }
 
 R_API const char *r_num_calc_index (RNum *num, const char *p) {
-	if (num == NULL)
-		return NULL;
+	if (!num) return NULL;
 	if (p) {
 		num->nc.calc_buf = p;
 		num->nc.calc_len = strlen (p);
 		num->nc.calc_i = 0;
-	} else {
-		num->nc.calc_buf = NULL;
-		num->nc.calc_len = 0;
-		num->nc.calc_i = 0;
 	}
-	//if (num->nc.calc_i>num->nc.calc_len) return NULL;
 	return num->nc.calc_buf + num->nc.calc_i;
 }
 
diff --git a/libr/util/num.c b/libr/util/num.c
index 041784d3ccbc3..907662d94f923 100644
--- a/libr/util/num.c
+++ b/libr/util/num.c
@@ -119,8 +119,9 @@ R_API ut64 r_num_get(RNum *num, const char *str) {
 		if (ok) return ret;
 	}
 
-	if (str[0]=='\'' && str[2]=='\'')
-		return (ut64)str[1];
+	if (str[0] && str[1] && str[2])
+		if (str[0]=='\'' && str[2]=='\'')
+			return (ut64)str[1];
 
 	len = strlen (str);
 	if (len>3 && str[4] == ':') {