diff --git a/VERSION b/VERSION
index 3773b88..66b8484 100644
--- a/VERSION
+++ b/VERSION
@@ -1,2 +1,2 @@
-2021 May 23 2021
+2021 May 25 2021
 
diff --git a/abcmatch.c b/abcmatch.c
index 8b98a19..9e5e505 100644
--- a/abcmatch.c
+++ b/abcmatch.c
@@ -49,7 +49,7 @@ Matching:
 
 
 
-#define VERSION "1.78 March 27 2021 abcmatch"
+#define VERSION "1.79 May 25 2021 abcmatch"
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
diff --git a/doc/CHANGES b/doc/CHANGES
index 94c31cb..03134fc 100644
--- a/doc/CHANGES
+++ b/doc/CHANGES
@@ -14240,3 +14240,14 @@ to get these options working again.
 
 
 
+May 25 2021
+
+James Allwright added more security checks to stop the
+parser from reading numbers beyond the largest integer. Changes
+were made to parserabc.c and midi2abc.c
+
+The abc2abc -s spacing function was modified to ignore certain
+time signatures like M: none or M:7/8. The code for dealing with
+3/2, 3/4, 3/8 ... time signatures was improved.
+
+
diff --git a/doc/readme.txt b/doc/readme.txt
index 89019bf..21c8f2c 100644
--- a/doc/readme.txt
+++ b/doc/readme.txt
@@ -1,10 +1,10 @@
 abcMIDI :   abc <-> MIDI conversion utilities
 
-midi2abc version 3.47 November 01 2020
-abc2midi version 4.56 May 21 2021
-abc2abc  version 2.13 May 08 2021
-yaps     version 1.86 December 10 2020
-abcmatch version 1.78 March 27 2021
+midi2abc version 3.47 May 25 2021
+abc2midi version 4.57 May 25 2021
+abc2abc  version 2.15 May 25 2021
+yaps     version 1.87 May 25 2021
+abcmatch version 1.79 May 25 2021
 midicopy version 1.37 October 10 2020
 
 24th January 2002
diff --git a/midi2abc.c b/midi2abc.c
index 9061e2c..c36105e 100644
--- a/midi2abc.c
+++ b/midi2abc.c
@@ -45,8 +45,9 @@
  * based on public domain 'midifilelib' package.
  */
 
-#define VERSION "3.47 November 01 2020 midi2abc"
+#define VERSION "3.48 May 25 2021 midi2abc"
 
+#include <limits.h>
 /* Microsoft Visual C++ Version 6.0 or higher */
 #ifdef _MSC_VER
 #define snprintf _snprintf
@@ -3451,7 +3452,8 @@ char *num;
     p = p + 1;
     neg = -1;
   };
-  while (((int)*p >= '0') && ((int)*p <= '9')) {
+  /* [JA] 2021-05-25 */
+  while (((int)*p >= '0') && ((int)*p <= '9') && (t < (INT_MAX-9)/10)) {
     t = t * 10 + (int) *p - '0';
     p = p + 1;
   };
@@ -3467,10 +3469,15 @@ char **p;
   int t;
   
   t = 0;
-  while (((int)**p >= '0') && ((int)**p <= '9')) {
+  /* [JA] 2021-05-25 */
+  while (((int)**p >= '0') && ((int)**p <= '9') && (t < (INT_MAX-9)/10)) {
     t = t * 10 + (int) **p - '0';
     *p = *p + 1;
   };
+  /* advance over any spurious extra digits */
+  while (isdigit(**p)) {
+    *p = *p + 1;
+  }
   return t;
 }
 
diff --git a/parseabc.c b/parseabc.c
index 81b471c..b5c36c3 100644
--- a/parseabc.c
+++ b/parseabc.c
@@ -37,6 +37,7 @@
 #include <stdlib.h>
 /* [JM] 2018-02-22 to handle strncasecmp() */
 #include <string.h>
+#include <limits.h>
 
 /* #define SIZE_ABBREVIATIONS ('Z' - 'H' + 1) [SS] 2016-09-20 */
 #define SIZE_ABBREVIATIONS 58
@@ -348,11 +349,15 @@ readnumf (num)
       event_error ("Missing Number");
     };
   t = 0;
-  while (((int) *p >= '0') && ((int) *p <= '9'))
+/* [JA] 2021-05-25 */
+  while (((int) *p >= '0') && ((int) *p <= '9') && (t < (INT_MAX-9)/10))
     {
       t = t * 10 + (int) *p - '0';
       p = p + 1;
     };
+  if (t >= (INT_MAX-9)/10) {  /* [JA] 2021-05-25 */
+    event_error ("Number too big");
+  }
   return (t);
 }
 
@@ -384,11 +389,16 @@ readnump (p)
   int t;
 
   t = 0;
-  while (((int) **p >= '0') && ((int) **p <= '9'))
-    {
-      t = t * 10 + (int) **p - '0';
-      *p = *p + 1;
-    };
+  /* [JA] 2021-05-25 */
+  while (((int) **p >= '0') && ((int) **p <= '9') && (t < (INT_MAX-9)/10))
+  {
+    t = t * 10 + (int) **p - '0';
+    *p = *p + 1;
+  }
+  /* advance over any spurious extra digits [JA] 2021-05-25 */
+  while (isdigit(**p)) {
+    *p = *p + 1;
+  }
   return (t);
 }
 
diff --git a/store.c b/store.c
index 819c7e6..2b59f7f 100644
--- a/store.c
+++ b/store.c
@@ -186,7 +186,7 @@ int main()
 
 */
 
-#define VERSION "4.56 May 21 2021 abc2midi" 
+#define VERSION "4.57 May 25 2021 abc2midi" 
 
 /* enables reading V: indication in header */
 #define XTEN1 1
diff --git a/toabc.c b/toabc.c
index f13371f..56eab22 100644
--- a/toabc.c
+++ b/toabc.c
@@ -21,7 +21,7 @@
 
 /* back-end for outputting (possibly modified) abc */
 
-#define VERSION "2.14 May 09 2021 abc2abc"
+#define VERSION "2.15 May 25 2021 abc2abc"
 
 /* for Microsoft Visual C++ 6.0 or higher */
 #ifdef _MSC_VER
@@ -84,6 +84,7 @@ struct fract breakpoint; /* used to break bar into beamed sets of notes */
 complex_barpoint_t master_bar_break;
 int barno; /* number of bar within tune */
 int newspacing; /* was -s option selected ? */
+int have_spacing_scheme; /* do we support spacing for time signature ? [JA] */
 int barcheck; /* indicate -b and -r options selected */
 int echeck; /* was error-checking turned off ? (-e option) */
 int newbreaks; /* was -n option selected ? */
@@ -575,6 +576,7 @@ char** filename;
   } else {
     newspacing = 1;
   };
+  have_spacing_scheme = 0; /* [JA] 2021-05-25 */
   narg = getarg("-X", argc, argv);
   if (narg == -1) {
     newrefnos = 0;
@@ -1414,6 +1416,7 @@ static void set_complex_barpoint(timesig_details_t *timesig,
 void event_timesig (timesig)
   timesig_details_t *timesig;
 {
+  have_spacing_scheme = 0; /* default to no new spacing */
   emit_string ( "M:");
   switch (timesig->type) {
     default:
@@ -1459,6 +1462,7 @@ void event_timesig (timesig)
           set_complex_barpoint(
             &current_voice->timesig, &toabc_voice->bar_break);
         }
+        have_spacing_scheme = 1; /* [JA] 2021-05-25 */
       }
       break;
   }
@@ -1470,16 +1474,28 @@ void event_timesig (timesig)
 
     breakpoint.num = timesig->num;
     breakpoint.denom = timesig->denom;
+    if (timesig->num == 3) {  /* [JA] 2021-05-25 */
+      /* handles 3/2, 3/4, 3/8 */
+      breakpoint.num = timesig->num / 3;
+      breakpoint.denom = timesig->denom;
+      have_spacing_scheme = 1;
+    }
     if ((timesig->num == 9) || (timesig->num == 6)) {
       breakpoint.num = 3;
       breakpoint.denom = barlen.denom;
+      have_spacing_scheme = 1;
     };
     if (timesig->num % 2 == 0) {
       breakpoint.num = barlen.num / 2;
       breakpoint.denom = barlen.denom;
+      have_spacing_scheme = 1;
     };
     barend = timesig->num / breakpoint.num;
   }
+  if (newspacing && !have_spacing_scheme) {
+    /* [JA] 2021-05-25 */
+    event_warning ("Do not know how to group notes in this time signature");
+  }
   inmusic = 0;
 }
 
@@ -1874,7 +1890,7 @@ char* replist;
 
 void event_space()
 {
-  if (!newspacing) {
+  if (!(newspacing && have_spacing_scheme)) {
     emit_string(" ");
   };
 }
@@ -1929,7 +1945,7 @@ int n, q, r;
   if (tuplenotes != 0) {
     event_error("tuple within tuple not allowed");
   };
-  if (newspacing) {
+  if (newspacing && have_spacing_scheme) {
     emit_char(' ');
   }
   emit_int_sprintf("(%d", n);
@@ -2504,7 +2520,7 @@ int xoctave, n, m;
   if ((!ingrace) && (!inchord)) {
     addunits(n, m);
   };
-  if (newspacing) {
+  if (newspacing && have_spacing_scheme) {
     consider_break_after_note(prev_tuplenotes);
   };
 }
@@ -2594,7 +2610,7 @@ int xoctave, n, m;
   if ((!ingrace) && (!inchord)) {
     addunits(n, m);
   };
-  if (newspacing) {
+  if (newspacing && have_spacing_scheme) {
     barpoint.num = count.num * breakpoint.denom;
     barpoint.denom = breakpoint.num * count.denom;
     reduce(&barpoint.num, &barpoint.denom);
diff --git a/yapstree.c b/yapstree.c
index c193b79..cb49711 100644
--- a/yapstree.c
+++ b/yapstree.c
@@ -22,7 +22,7 @@
 /* yapstree.c - back-end for abc parser. */
 /* generates a data structure suitable for typeset music */
 
-#define VERSION "1.86 December 10 2020 yaps"
+#define VERSION "1.87 May 25 2021 yaps"
 #include <stdio.h>
 #ifdef USE_INDEX
 #define strchr index