[rdesktop-devel] Configure Fails to Detect Header On First Run

[Christian B. <cs...@gm...>]

I'm having a problem getting the rdesktop configure script to  
correctly detect a header file when used with Andrew Joyce's dual- 
monitor patch that he sent to the list earlier in the summer.  
Although the patch isn't an official part of rdesktop, I'm wondering  
if the problem is in the configure script.

Here's what happens:
I download the 1.5.0-rc1 or 1.5.0-final source tarball and unpack it,  
then apply Andrew's patch and run ./configure && make. The configure  
does not detect the Xinerama.h header in /usr/lib, and so the make  
fails. Immediately after the make fails, if I run ./configure && make  
again, configure detects the Xinerama.h header in /usr/lib and  
rdesktop builds successfully. Even if the first unsuccessful  
configure is run multiple times before a make is attempted, the  
Xinerama.h header is not detected. However, as soon as make is run  
once, all subsequent configures will correctly detect the Xinerama.h  
header in /usr/lib.

So again, the process is:
1) Unstuff source/apply patch
2) ./configure: Any number of times, /usr/lib/Xinerama.h not detected
3) make: fails
4) ./configure: /usr/lib/Xinerama.h detected
5) make: succeeds

Andrew's patch (http://six27.com/files/dual-monitor-fix.patch) makes  
the following changes to configure.ac:
AC_CHECK_HEADER(langinfo.h, AC_DEFINE(HAVE_LANGINFO_H))
+AC_CHECK_LIB(Xinerama, XineramaQueryScreens, AC_DEFINE 
(HAVE_XINERAMA) LIBS="$LIBS -lXinerama", [], [])
AC_CHECK_TOOL(STRIP, strip, :)

Between the first unsuccessful configure and the second successful  
post-make configure, I have diffed both the configure --cache-file  
output and the resulting Makefiles. The only difference is that in  
the second successful post-make configure, the --cache-file output  
adds the line:
ac_cv_lib_Xinerama_XineramaQueryScreens=$ 
{ac_cv_lib_Xinerama_XineramaQueryScreens=yes}
...and the Makefile adds '-DHAVE_XINERAMA=1' to CFLAGS and '- 
lXinerama' to LDFLAGS.

I'm stumped why configure isn't picking up /usr/lib/Xinerama.h the  
first time around. Can somebody point out what I've done wrong?

-- 
Christian Bell  ::  cs...@gm...