Fix crash if "@return" Doxygen tag was used on a node without any return
type (such as a class, for example). Ignoring it might not be the best
thing to do, but it's definitely better than crashing and it's not
really clear what else could be done anyhow.
Closes#1516.
Found via `codespell -q 3 -L "uint,bae,objext,cmo,goin,struc,ois,upto"`
whitespaces were unintentionally fixed due to my editors settings.
Rebased patch #1327
One Doxygen test file used "#" for comments for some reason, this doesn't work
with the latest SWIG trunk where a lone "#" is considered to be an unknown
preprocessor directive.
Silently ignoring unknown Doxygen commands is not a reasonable default
behaviour, it's simple enough to turn off the warning if the command is really
supposed to be just ignored, but it's too easy to not notice a real problem if
it isn't.
Turn WARN_DOXYGEN_UNKNOWN_COMMAND on by default and add a test to the errors
test suite checking that it is indeed given.
This is important to preserve the structure of the lists which appear
correctly in Python output without any additional effort if the indentation is
lost.
It is also makes the behaviour consistent for
/**
*
*
*/
comments and those without the asterisks in the middle lines, as now the
indentation is preserved in both cases while it was only preserved when the
asterisks were present previously.
