--- gap/basic/grphoms.gi.orig	2020-07-24 17:55:13.000000000 -0600
+++ gap/basic/grphoms.gi	2022-09-11 10:29:16.792073715 -0600
@@ -158,6 +158,10 @@ function( hom )
     gens := hom!.igs_gens_to_imgs[1];
     imgs := hom!.igs_gens_to_imgs[2];
 
+    if Length(gens) = 0 then
+        return true;
+    fi;
+
     # check relators
     for i in [1..Length( gens )] do
         if RelativeOrderPcp( gens[i] ) > 0 then
@@ -216,6 +220,10 @@ function( hom )
 
     C := TrivialSubgroup(Range(hom)); # the cokernel
 
+    if Length(gens) = 0 then
+        return C;
+    fi;
+
     # check relators
     for i in [1..Length( gens )] do
         if RelativeOrderPcp( gens[i] ) > 0 then