Behavior of synIDattr() varies

[Thomas Haselwanter]

Hi,

Vims excellent script support just asks to be exploited, and I am in the 
process of putting 2html.vim to use. I have been getting different 
results from this script, which I've tracked down to synIDattr() 
returning different attribute values for given syntax IDs depending upon 
the environment from which vim is called.

Calling

/usr/bin/vim -e +"syntax on" +"set syntax=c" +"run! syntax/2html.vim" 
+"wq" +"q" /tmp/helloworld.c

from the command line results in a different HTML file than calling it 
via a system call from within mod_perl. In particular synIDattr() 
doesn't return "1" anymore for the attribute bold and for the fg 
attribute it maps to different cterm colors, even two different colors 
to the same cterm color which weakens the highlighting effect. This is 
not a switch from 8 cterm colors to 16 or vice versa, both work with 8 
colors.

I realize that this may possibly need to be fixed in mod_perl and not 
vim, but at this stage I'm just fishing for pointers what might cause 
synIDattr() to behave differently. I've verified this behavior in vim 
6.3 and the latest 7.0 beta. Any ideas?

Thomas