fixes #2625

tests/collections/tcounttable.nim

@@ -0,0 +1,19 @@
+discard """
+  output: "And we get here"
+"""
+
+# bug #2625
+
+const s_len = 32
+
+import tables
+var substr_counts: CountTable[string] = initCountTable[string]()
+var my_string = "Hello, this is sadly broken for strings over 64 characters. Note that it *does* appear to work for short strings."
+for i in 0..(my_string.len - s_len):
+  let s = my_string[i..i+s_len-1]
+  substr_counts[s] = 1
+  # substr_counts[s] = substr_counts[s] + 1  # Also breaks, + 2 as well, etc.
+  # substr_counts.inc(s)  # This works
+  #echo "Iteration ", i
+
+echo "And we get here"