From 0672eec7fba97639e3e8e46bfee2fd8578789f0b Mon Sep 17 00:00:00 2001
From: Thierry Gosselin <thierrygosselin@icloud.com>
Date: Wed, 9 Sep 2026 13:39:16 +1000
Subject: [PATCH] Validate genotype error matrix input

---
 abcGL.cpp | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/abcGL.cpp b/abcGL.cpp
index 7ff20aa..a374f3a 100644
--- a/abcGL.cpp
+++ b/abcGL.cpp
@@ -38,7 +38,7 @@ void readError(double **errors,const char *fname){
   FILE *fp=NULL;
   if(NULL==(fp=fopen(fname,"r"))){
     fprintf(stderr,"Error opening file: %s\n",fname);
-    exit(0);
+    exit(EXIT_FAILURE);
   }
   
   char buf[LENS];
@@ -47,11 +47,23 @@ void readError(double **errors,const char *fname){
 
   int nLines =0;
   while(fgets(buf,LENS,fp)){
-    res[0] += atof(strtok(buf," \t\n"));
-    for(int i=1;i<16;i++)
-      res[i] += atof(strtok(NULL," \t\n"));
+    char *token = strtok(buf," \t\n");
+    for(int i=0;i<16;i++) {
+      if(token == NULL) {
+        fprintf(stderr,"Error parsing error matrix %s on line %d: expected 16 numeric fields.\n", fname, nLines + 1);
+        fclose(fp);
+        exit(EXIT_FAILURE);
+      }
+      res[i] += atof(token);
+      token = strtok(NULL," \t\n");
+    }
     nLines ++;
   }
+  if(nLines == 0) {
+    fprintf(stderr,"Error parsing error matrix %s: file is empty.\n", fname);
+    fclose(fp);
+    exit(EXIT_FAILURE);
+  }
   for(int j=0;j<16;j++)
     fprintf(stderr,"%f\t",res[j]);
   fprintf(stderr,"\nEstimating errors using nChunks:%d\n",nLines);