tree 32f3b3fbd5a3611b50211b223d027191faaafca9
parent 269b753496180cdb3082d87b0cd907905593dee5
author John Bowler <jbowler@acm.org> 1705622312 -0800
committer John Bowler <jbowler@acm.org> 1705628219 -0800

tests/pngtest-all: detect failures add tests

This change is only verifiable in configure builds; cmake only executes
the basic test.

The previous version of tests/pngtest-all only returned the status code
of the final test.  Apparently it could never fail.  This adds checking
of all return status codes.

The change also adds a basic approach for regression testing with PNGs
that should fail a test; --strict ensures that PNGs which are valid do
not start to be reported as erroneous, this is the inverse.

At present the code (minimal traditional Bourne shell) only tests the
palette index checking code, a potentially important check if apps rely
on it.

The changes have been tested using the configure build both with a
regression which causes the libpng checking to cease to work and with a
corrected (reverted regression).  The regression test verifies that the
intended check works as expected.

Signed-off-by: John Bowler <jbowler@acm.org>