[PATCH] Make CONFIG_SITE handling more robust.

[Eric Blake]

* lib/autoconf/general.m4 (AC_SITE_LOAD): Avoid leading - and path
search, and check for failure to load.
* tests/base.at (AC_CACHE_CHECK): Enhance test.
* doc/autoconf.texi (Site Defaults): Mention that CONFIG_SITE
works best as an absolute path.
* NEWS: Document the semantic change.

Signed-off-by: Eric Blake <address@hidden>
---

> > Should I squash these patches into one before pushing?
> However you like.
>
> Does the manual and NEWS need an update that $PATH-findable $CONFIG_SITE
> are not allowed any more?  I'm not actually sure whether this is used in
> practice now, but it could be construed as a feature, no?

Here's what I finally pushed; squashing all three proposals into
one patch and incorporating your comment.

 ChangeLog               |   10 ++++++++++
 NEWS                    |    3 +++
 doc/autoconf.texi       |    3 ++-
 lib/autoconf/general.m4 |   10 ++++++++--
 tests/base.at           |   18 ++++++++++++++++--
 5 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index c0c4bc0..ce07880 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2010-06-10  Eric Blake  <address@hidden>
+
+       Make CONFIG_SITE handling more robust.
+       * lib/autoconf/general.m4 (AC_SITE_LOAD): Avoid leading - and path
+       search, and check for failure to load.
+       * tests/base.at (AC_CACHE_CHECK): Enhance test.
+       * doc/autoconf.texi (Site Defaults): Mention that CONFIG_SITE
+       works best as an absolute path.
+       * NEWS: Document the semantic change.
+
 2010-03-13  Bruno Haible  <address@hidden>
        and Ralf Wildenhues  <address@hidden>

diff --git a/NEWS b/NEWS
index 5c0d130..3e1155c 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,9 @@ GNU Autoconf NEWS - User visible changes.
    and `--with-*' arguments, converting them to underscores for the variable
    names.

+** In configure scripts, loading CONFIG_SITE no longer searches PATH,
+   and problems in loading the configuration site files are diagnosed.
+
 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
   Released by Eric Blake, based on git versions 2.64.*.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 519158c..42469db 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -20980,7 +20980,8 @@ Site Defaults

 @evindex CONFIG_SITE
 If the environment variable @code{CONFIG_SITE} is set, @command{configure}
-uses its value as the name of a shell script to read.  Otherwise, it
+uses its value as the name of a shell script to read; it is recommended
+that this be an absolute file name.  Otherwise, it
 reads the shell script @address@hidden/share/config.site} if it exists,
 then @address@hidden/etc/config.site} if it exists.  Thus,
 settings in machine-specific files override those in machine-independent
diff --git a/lib/autoconf/general.m4 b/lib/autoconf/general.m4
index e764b16..cadec67 100644
--- a/lib/autoconf/general.m4
+++ b/lib/autoconf/general.m4
@@ -1870,7 +1870,12 @@ m4_define([AC_SITE_LOAD],
 ac_site_file1=NONE
 ac_site_file2=NONE
 if test -n "$CONFIG_SITE"; then
-  ac_site_file1=$CONFIG_SITE
+  # We do not want a PATH search for config.site.
+  case $CONFIG_SITE in @%:@((
+    -*)  ac_site_file1=./$CONFIG_SITE;;
+    */*) ac_site_file1=$CONFIG_SITE;;
+    *)   ac_site_file1=./$CONFIG_SITE;;
+  esac
 elif test "x$prefix" != xNONE; then
   ac_site_file1=$prefix/share/config.site
   ac_site_file2=$prefix/etc/config.site
@@ -1884,7 +1889,8 @@ do
   if test /dev/null != "$ac_site_file" && test -r "$ac_site_file"; then
     AC_MSG_NOTICE([loading site script $ac_site_file])
     sed 's/^/| /' "$ac_site_file" >&AS_MESSAGE_LOG_FD
-    . "$ac_site_file"
+    . "$ac_site_file" \
+      || AC_MSG_FAILURE([failed to load site script $ac_site_file])
   fi
 done
 ])
diff --git a/tests/base.at b/tests/base.at
index 54ccd8a..8f6e30f 100644
--- a/tests/base.at
+++ b/tests/base.at
@@ -258,6 +258,7 @@ AT_CLEANUP
 # Also make sure we warn about cache id's not named with `_cv_'.

 AT_SETUP([AC_CACHE_CHECK])
+AT_KEYWORDS([CONFIG_SITE])

 # Don't let a config.site file affect this test.
 AS_UNSET([CONFIG_SITE])
@@ -395,13 +396,14 @@ AT_CHECK([grep cache stdout], [1])
 AT_CHECK([LC_ALL=C ls -t config.cache a-stamp-file | sed 1q | grep 
config.cache], [1])

 # config.site can specify a site-wide cache, accumulating information.
-AT_DATA([config.site],
+# Also test that we don't run afoul of sourcing a file with leading -.
+AT_DATA([-config.site],
 [[cache_file=sitecache
 ]])
 AT_DATA([sitecache],
 [[my_cv_some_preset_cache_var=yes
 ]])
-CONFIG_SITE=config.site
+CONFIG_SITE=-config.site
 export CONFIG_SITE
 AT_CHECK_CONFIGURE
 AT_CHECK([grep my_cv_some_preset_cache_var sitecache], [], [ignore])
@@ -409,6 +411,18 @@ AT_CHECK([grep my_cv_shell_true_works sitecache], [], 
[ignore])
 AT_CHECK_CONFIGURE([], [], [stdout])
 AT_CHECK([grep 'whether true.*works.*cached' stdout], [], [ignore])

+# Check that config cache scripts must be well-formed.
+AT_DATA([bad.site],
+[[fi
+]])
+CONFIG_SITE=$PWD/bad.site
+AT_CHECK_CONFIGURE([], [1], [ignore], [stderr])
+AT_CHECK([grep 'failed to load site script' stderr], [], [ignore])
+
+# However, a missing file is ignored.
+CONFIG_SITE=./no-such-file
+AT_CHECK_CONFIGURE
+
 AT_CLEANUP


-- 
1.7.0.1