PPD parser: Calling cupsFileGetChar(...) after EOF

[ppawliczek]

For some input data the function cupsFileGetChar(...) was incorrectly called
from the function ppd_read(...) after returning EOF in a previous call. This
causes incorrect state of cups_file and results in memory leak.

[michaelrsweet]

That's not the right place to add this check. I've committed a change to the cupsFileGetChar and cupsFileRead functions to immediately return EOF rather than calling cups_fill.

[master 96fee30] Protect against continuing to read from a file at EOF (Issue #5473)

[michaelrsweet]

[branch-2.2 18518f3] Protect against continuing to read from a file at EOF (Issue #5473)