title: Ghostscript /stackunderflow in CMap definition
body: <p>I'm trying to create a simple CMap with mapping for two CIDs. Any idea what's wrong with following CMap?</p>
  <pre><code>/CIDInit /ProcSet findresource begin
  13 dict begin
  begincmap /CIDSystemInfo &lt;&lt;
  /Registry (Adobe) /Ordering (Identity) /Supplement 0 &gt;&gt; def
  /CMapName /CM def
  /CMapType 1 def
  1 begincodespacerange
  &lt;00&gt; &lt;02&gt;
  endcodespacerange
  
  2 begincidchar
  &lt;01&gt; 6691
  &lt;02&gt; 6692
  endcidchar
  endcmap CMapName currentdict /CMap defineresource
  pop end end
  </code></pre>
  <p>gs interpreter throws following error:</p>
  <pre><code>Error: /stackunderflow in --index--
  Operand stack:
     1   --nostringval--   (\002)   6691   (\001)   (\000\000\000\002)   ()   (\032#)   0   (\001)   10
  Execution stack:
     %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push   1992   1   3   %oparray_pop   1991   1   3   %oparray_pop   1979   1   3   %oparray_pop   1833   1   3   %oparray_pop   --nostringval--   %errorexec_pop   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   1   --nostringval--   %repeat_continue   --nostringval--   --nostringval--
  Dictionary stack:
     --dict:730/1123(ro)(G)--   --dict:0/20(G)--   --dict:75/200(L)--   --dict:38/38(ro)(G)--   --dict:8/13(L)--
  Current allocation mode is local
  Current file position is 270
  GPL Ghostscript 9.27: Unrecoverable error, exit code 1
  </code></pre>