Re: Patch: install libgtkpeer.so and libjawt.so in versioned library directory

[Andrew Haley <aph at redhat dot com>]

Thomas Fitzsimmons writes:

 > +
 > +  // Check if LD_LIBRARY_PATH is already prefixed with
 > +  // GCJ_VERSIONED_LIBDIR.  If not, export LD_LIBRARY_PATH prefixed
 > +  // with GCJ_VERSIONED_LIBDIR and re-spawn gij.
 > +  char *libpath = getenv (LTDL_SHLIBPATH_VAR);
 > +  char *newpath = _Jv_PrependVersionedLibdir (libpath);
 > +
 > +  if (! libpath || strcmp (libpath, newpath))
 > +    {
 > +      setenv (LTDL_SHLIBPATH_VAR, newpath, 1);
 > +      JvFree (newpath);
 > +
 > +      int error_code = execv (GIJ_EXECUTABLE, (char* const*) argv);

But, as discussed with Bryce, the version in svn is

     int error_code = execvp (argv[0], (char* const*) argv);

This can break java-1.4.2-gcj-compat.

/usr/bin/java prefixes the LD_LIBRARY_PATH with the gij install dir.
Then, /usr/bin/java does an execv of PREFIX/gij, but it leaves argv[0]
pointing to /usr/bin/java rather than PREFIX/gij.

So, when you call execvp(), the /usr/bin/java wrapper is re-executed,
not gij.  This in turn, re-executes gij, ad nauseam.

So, to make this clear:

/usr/bin/java prefixes LD_LIBRARY_PATH and execs gij
gij prefixes LD_LIBRARY_PATH and execs /usr/bin/java
/usr/bin/java prefixes LD_LIBRARY_PATH and execs gij
gij prefixes LD_LIBRARY_PATH and execs /usr/bin/java
...

This doesn't happen if you use GIJ_EXECUTABLE instead of argv[0].
Everything works correctly.

You either need to go back to using GIJ_EXECUTABLE or make the test
for the already prefixed GCJ_VERSIONED_LIBDIR better.  Perhaps you
could set a special evironment variable and detect that?

Andrew.