potential AC_LIBTOOL_SYS_MAX_CMD_LEN bug

[Willem Jan Palenstijn]

Hi,

I encountered a problem today while running a configure (from GemRB
(gemrb.sf.net)) generated by autoconf 2.59 with a libtool.m4 from libtool
1.5.2.

I started configure with "bash configure" and did not have
$CONFIG_SHELL set. Note that in this case $0 equals "configure".

configure contains the following test from libtool.m4 in the 
AC_LIBTOOL_SYS_MAX_CMD_LEN macro:

test "X"`$CONFIG_SHELL $0 --fallback-echo "X$testring" 2>/dev/null` == 
"XX$testring"

This test will always fail, since "$CONFIG_SHELL $0" expands to
" configure", which is not in my path (since "." is not in my $PATH). This 
results in max_cmd_len being empty, which is clearly undesirable.

I double-checked this by adding the line:

echo `$CONFIG_SHELL $0 --fallback-echo "XX" 2>/dev/null`

to configure just above the test, and it indeed produced an empty line
when configure was run as "bash configure" and "XX", as expected,
when run as "./configure".

In other words, I do not think $CONFIG_SHELL can be used for this
purpose at this point in libtool.m4.

If you need any other info, I'll be happy to provide it.

Thanks,
Willem Jan