[QGIS-Developer] Is qgis_sip_uptodate test giving false negative ?

[Sandro Santilli]

Looking at Travis output, the qgis_sip_uptodate test passes:

  https://travis-ci.org/qgis/QGIS/jobs/591915632#L958

BUT a test I've added to check if repository files changed
shows that the `python/server/server_auto.sip` file in the
git repository was changed during tests:

  https://travis-ci.org/qgis/QGIS/jobs/591915632#L941-L944

Are the two facts contraddictory ?

Reading scripts/sipify.pl it looks like the `-p` switch is
not supported, while the `-s` switch is used for two different
switches (a typo?):

    GetOptions ("debug" => \$debug, "sip_output=s" => \$sip_output,
							  "python_output=s" => \$python_output) && @ARGV == 1;

I mention this because tests/code_layout/test_sipfiles_uptodate.sh
uses the -p switch instead:

		./scripts/sipify.pl -p python/${module}/auto_additions/${pyfile}.temp $header |
				diff python/$sipfile.in -

So, I suspect sipify.pl is _overriding_ the source file and NEVER producing
a .temp file, resulting in:

  1) A false OK message from Travis (no difference!)
	2) A modification of source tree during test

--strk;