Bug 1660610

Description of problem:
When I try to print a plain text file, nothing comes out of the printer. If I change the LogLevel in cupsd.conf to debug, I see error messages in /var/log/cups/error_log saying "Error: /typecheck in /findfont". It seems that
the Postscript is generated by paps. I get a similar error when I run
"head /etc/passwd | paps | gs -".

Version-Release number of selected component (if applicable):
paps-0.6.8-28.el7.1.x86_64


How reproducible:
Always.

Steps to Reproduce:
1. head /etc/passwd | lpr
2. or 
3. head /etc/passwd | paps | gs -

Actual results:
Error messages, and nothing is printed. Here's what I see:
bash-4.2$ head /etc/passwd | paps | gs -
GPL Ghostscript 9.07 (2013-02-14)
Copyright (C) 2012 Artifex Software, Inc.  All rights reserved.
This software comes with NO WARRANTY: see the file PUBLIC for details.
Can't find (or can't open) font file /usr/share/ghostscript/9.07/Resource/Font/NimbusSanL-Regu.
Can't find (or can't open) font file NimbusSanL-Regu.
Can't find (or can't open) font file /usr/share/ghostscript/9.07/Resource/Font/NimbusSanL-Regu.
Can't find (or can't open) font file NimbusSanL-Regu.
Querying operating system for font files...
Error: /typecheck in /findfont
Operand stack:
   Helvetica
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push   1884   1   3   %oparray_pop   1883   1   3   %oparray_pop   1867   1   3   %oparray_pop   1755   1   3   %oparray_pop   --nostringval--   %errorexec_pop   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   --nostringval--   1836   1   5   %oparray_pop
Dictionary stack:
   --dict:950/1684(ro)(G)--   --dict:0/20(G)--   --dict:78/200(L)--   --dict:27/42(L)--   --dict:11/11(L)--
Current allocation mode is local
GPL Ghostscript 9.07: Unrecoverable error, exit code 1

That's very similar to what I see in /var/log/cups/error_log, except it doesn't specify which fonts are not found. In error_log, I see:
D [18/Dec/2018:14:23:23 -0500] [Job 139] Before copy_comments - %!PS-Adobe-3.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] %!PS-Adobe-3.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] %cupsRotation: 0
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%Title: (stdin)
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%Creator: paps version 0.6.7 by Dov Gr
obgeld
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%Pages: (atend)
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%BoundingBox: 0 0 612 792
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%For: schorr
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%Orientation: Portrait
D [18/Dec/2018:14:23:23 -0500] [Job 139] %%EndComments
D [18/Dec/2018:14:23:23 -0500] [Job 139] Before copy_prolog - %%BeginProlog
D [18/Dec/2018:14:23:23 -0500] [Job 139] Before copy_setup - %%BeginSetup
D [18/Dec/2018:14:23:23 -0500] [Job 139] Before page loop - %%Page: 1 1
D [18/Dec/2018:14:23:23 -0500] [Job 139] Copying page 1...
D [18/Dec/2018:14:23:23 -0500] [Job 139] pagew = 588.0, pagel = 768.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] bboxx = 0, bboxy = 0, bboxw = 612, bbox
l = 792
D [18/Dec/2018:14:23:23 -0500] [Job 139] PageLeft = 12.0, PageRight = 600.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] PageTop = 780.0, PageBottom = 12.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] PageWidth = 612.0, PageLength = 792.0
D [18/Dec/2018:14:23:23 -0500] [Job 139] Wrote 1 pages...
D [18/Dec/2018:14:23:23 -0500] [Job 139] Error: /typecheck in /findfont
D [18/Dec/2018:14:23:23 -0500] [Job 139] Operand stack:
D [18/Dec/2018:14:23:23 -0500] [Job 139] Helvetica
...

Expected results:
It should work!

Additional info: I am not certain which component is at fault, but clearly it cannot find the fonts that it wants.