==8630== Invalid read of size 8
==8630==    at 0x4EA4F0F: virFree (viralloc.c:582)
==8630==    by 0x4F398F0: virXMLValidatorFree (virxml.c:1257)
==8630==    by 0x40305C: mymain (virschematest.c:191)
==8630==    by 0x405159: virTestMain (testutils.c:982)
==8630==    by 0x403553: main (virschematest.c:215)
==8630==  Address 0xcd72243 is 131 bytes inside a block of size 177 free'd
==8630==    at 0x4C2B1F0: free (vg_replace_malloc.c:473)
==8630==    by 0x4EA4F19: virFree (viralloc.c:582)
==8630==    by 0x4ED0973: virFindFileInPath (virfile.c:1646)
==8630==    by 0x405149: virTestMain (testutils.c:980)
==8630==    by 0x403553: main (virschematest.c:215)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Failure to parse the schema file would not trigger a test suite failure.

In addition to making the test fail it's necessary to split up the
parsing of the schema file into a separate test.

This is necessary as the XML validator uses libvirt errors to report
problems parsing of the actual schema RNG needs to be split out into a
separate function and called via virTestRun which has the
infrastructure to report them.

This way we can safely differentiate what XMLs contain whole domain
definitions and which contain just devices.  Thanks to that we can
test the domain XMLs in virschematest again.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Switch from opendir to virDirOpen everywhere we need to report an error.

Introduce a helper that only calls closedir if DIR* is non-NULL
and sets it to NULL afterwards.

This function doesn't follow our convention of naming functions.

Jump to cleanup if virAsprintf fails.

So the story goes like this. The testSchemaDirs() function is
called with: a) the schema file, b) list of the directories that
contains XMLs documents that should be checked against the schema
file from a). However, the directories in the list are really
just their names and it's up to testSchemaDirs to construct the
absolute path and call testSchemaDir() which then does the actual
validation. The absolute path is constructed, but never actually
used (maybe due to a typo). Thus a VPATH build is broken.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Instead of calling xmllint via a shell script, use our virXMLValidator
API to do it directly via libxml.