From aacd0885df3f70805846f9149d28c1cdaf742d6a Mon Sep 17 00:00:00 2001
From: Enno Rehling <enno.rehling@gmail.com>
Date: Sun, 25 Feb 2018 19:17:20 +0100
Subject: [PATCH] fix termination bug in itoa functions.

---
 src/gmtool.c           |  2 +-
 src/kernel/unit.h      |  1 -
 src/util/base36.c      | 12 +++++++++---
 src/util/base36.h      |  1 +
 src/util/base36.test.c | 23 +++++++++++++++--------
 5 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/src/gmtool.c b/src/gmtool.c
index 6051ed9cc..65ca7fe07 100644
--- a/src/gmtool.c
+++ b/src/gmtool.c
@@ -1247,7 +1247,7 @@ static void handlekey(state * st, int c)
         else if (findmode == 'F') {
             faction *f = select_faction(st);
             if (f != NULL) {
-                itoab_r(f->no, 36, locate, sizeof(locate));
+                itoa36_r(f->no, locate, sizeof(locate));
                 findmode = 'f';
             }
             else {
diff --git a/src/kernel/unit.h b/src/kernel/unit.h
index b70082a4b..c242e0bd2 100644
--- a/src/kernel/unit.h
+++ b/src/kernel/unit.h
@@ -249,7 +249,6 @@ extern "C" {
     void remove_empty_units(void);
 
     struct unit *findunit(int n);
-
     struct unit *findunitr(const struct region *r, int n);
 
     void default_name(const unit *u, char name[], int len);
diff --git a/src/util/base36.c b/src/util/base36.c
index 3ded21a54..30020de30 100644
--- a/src/util/base36.c
+++ b/src/util/base36.c
@@ -58,7 +58,7 @@ const char *itoab_r(int i, int base, char *s, size_t len)
 
     assert(len > 2);
     dst = s + len - 2;
-    *dst = 0;
+    dst[1] = 0;
     if (i != 0) {
         int neg = 0;
 
@@ -92,12 +92,18 @@ const char *itoab_r(int i, int base, char *s, size_t len)
             assert(i == 0 || !"itoab: static buffer exhausted");
         }
     }
-    else
-        *dst = '0';
+    else {
+        dst[0] = '0';
+    }
 
     return dst;
 }
 
+const char *itoa36_r(int i, char *result, size_t len)
+{
+    return itoab_r(i, 36, result, len);
+}
+
 const char *itoab(int i, int base)
 {
     static char sstr[80];
diff --git a/src/util/base36.h b/src/util/base36.h
index 804952ab7..05c81d2c0 100644
--- a/src/util/base36.h
+++ b/src/util/base36.h
@@ -25,6 +25,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 extern "C" {
 #endif
 
+    const char *itoa36_r(int i, char *result, size_t len);
     const char *itoab_r(int i, int base, char *result, size_t len);
     const char *itoab(int i, int base);
     const char *itoa36(int i);
diff --git a/src/util/base36.test.c b/src/util/base36.test.c
index 226fd86ab..90d5b42f7 100644
--- a/src/util/base36.test.c
+++ b/src/util/base36.test.c
@@ -5,6 +5,7 @@
 #include <CuTest.h>
 #include "base36.h"
 #include <stdlib.h>
+#include <string.h>
 #include <limits.h>
 
 static void test_atoi36(CuTest * tc)
@@ -19,14 +20,20 @@ static void test_atoi36(CuTest * tc)
 
 static void test_itoa36(CuTest * tc)
 {
-  CuAssertStrEquals(tc, itoa36(0), "0");
-  CuAssertStrEquals(tc, itoa10(INT_MAX), "2147483647");
-  CuAssertStrEquals(tc, itoab(INT_MAX, 8), "17777777777");
-  CuAssertStrEquals(tc, itoab(INT_MAX, 4), "1333333333333333");
-  CuAssertStrEquals(tc, itoab(-1, 5), "-1");
-  CuAssertStrEquals(tc, itoa36(-1), "-1");
-  CuAssertStrEquals(tc, itoa36(-10), "-a");
-  CuAssertStrEquals(tc, itoa36(666), "ii");
+    char buf[10];
+    CuAssertStrEquals(tc, itoa36(0), "0");
+    CuAssertStrEquals(tc, itoa10(INT_MAX), "2147483647");
+    CuAssertStrEquals(tc, itoab(INT_MAX, 8), "17777777777");
+    CuAssertStrEquals(tc, itoab(INT_MAX, 4), "1333333333333333");
+    CuAssertStrEquals(tc, itoab(-1, 5), "-1");
+    CuAssertStrEquals(tc, itoa36(-1), "-1");
+    CuAssertStrEquals(tc, itoa36(-10), "-a");
+    CuAssertStrEquals(tc, itoa36(666), "ii");
+
+    memset(buf, 255, sizeof(buf));
+    CuAssertStrEquals(tc, itoa36_r(-10, buf, sizeof(buf)), "-a");
+    memset(buf, 255, sizeof(buf));
+    CuAssertStrEquals(tc, itoab_r(666, 36, buf, sizeof(buf)), "ii");
 }
 
 CuSuite *get_base36_suite(void)