Description of problem:
The fix for STR #4461 changes the way files in /etc/cups/ppd/ are created by cupsd. They are no longer world-readable.

Unfortunately, cupsGetPPD() assumes that if the files exist, they are world-readable, and so will return a symlink to a file in /etc/cups/ppd/ to the caller even though they will not be able to read it.

This causes numerous failures:
system-config-printer will not be able to edit any local queue
any gtk application will not be able to adjust printer options when printer
lpoptions -p <printer> -l will fail
etc...

Version-Release number of selected component (if applicable):
cups-1.6.3-16.el7

How reproducible:
100%

Steps to Reproduce:
1.sudo lpadmin -p foo -m drv:///sample.drv/generic.ppd -v socket://foo:9100 -E
2.lpoptions -p foo -l

Actual results:
lpoptions: Unable to open PPD file for foo.

Expected results:
PageSize/Media Size: Letter Legal Executive Tabloid A3 *A4 A5 B5 EnvISOB5 Env10 EnvC5 EnvDL EnvMonarch
InputSlot/Media Source: *Default Upper Manual
Duplex/2-Sided Printing: *None DuplexNoTumble DuplexTumble
Option1/Duplexer: *False True

Additional info:
Fix is for cupsGetPPD3() to check for readability.

See also bug #1150917, which is the Fedora equivalent of this.