diff -p -u -r automake_patch1/ChangeLog automake_patch2/ChangeLog
--- automake_patch1/ChangeLog	Thu Aug 16 20:59:00 2001
+++ automake_patch2/ChangeLog	Thu Aug 16 20:56:13 2001
@@ -1,5 +1,14 @@
 2001-08-16  Richard Boulton <address@hidden>
 
+	* automake.in (handle_dist): Out of date comment removed.
+	(variable_conditionally_defined): Updated to recurse itself,
+	rather than calling variable_conditions_recursive(): removes an
+	exponential complexity issue.  Also, fix comment defining method
+	and arguments.
+	(variable_conditionally_defined_sub): New function.
+
+2001-08-16  Richard Boulton <address@hidden>
+
 	* automake.in (extract_variable_reference): New function,
 	containing functionality which was previously repeated several
 	times.
diff -p -u -r automake_patch1/automake.in automake_patch2/automake.in
--- automake_patch1/automake.in	Thu Aug 16 20:59:00 2001
+++ automake_patch2/automake.in	Thu Aug 16 20:41:45 2001
@@ -3552,10 +3552,6 @@ sub handle_dist
 	# to all possible directories, and use it.  If DIST_SUBDIRS is
 	# defined, just use it.
 	my $dist_subdir_name;
-	# Note that we check DIST_SUBDIRS first on purpose.  At least
-	# one project uses so many conditional subdirectories that
-	# calling variable_conditionally_defined on SUBDIRS will cause
-	# automake to grow to 150Mb.  Sigh.
 	if (&variable_defined ('DIST_SUBDIRS')
 	    || variable_conditionally_defined ('SUBDIRS'))
 	{
@@ -6055,16 +6051,56 @@ sub variable_conditions ($)
 
 
 # $BOOLEAN
-# &variable_conditionally_defined ($VAR)
-# --------------------------------------
+# variable_conditionally_defined ($VAR)
+# -------------------------------------
+# Determines whether the variable $VAR is defined conditionally.
+# Returns true if the variable or a sub variable is defined conditionally.
 sub variable_conditionally_defined ($)
 {
     my ($var) = @_;
-    foreach my $cond (variable_conditions_recursive ($var))
-      {
+    %vars_scanned = ();
+    return variable_conditionally_defined_sub ($var, $var);
+}
+
+# $BOOLEAN
+# variable_conditionally_defined_sub ($VAR, $PARENT)
+# --------------------------------------------------
+# Do the work for variable_conditionally_defined.
+# Check if the variable
+#
+# Arguments:
+# $VAR    is the variable to check for conditional definition. 
+# $PARENT is the parent variable, used only for error messages.
+#
+# Returns true if the variable or a sub variable is defined conditionally.
+sub variable_conditionally_defined_sub ($$)
+{
+    my ($var, $parent) = @_;
+
+    if (defined $vars_scanned{$var})
+    {
+	&am_line_error ($var, "variable `$var' recursively defined");
+	return 0;
+    }
+    $vars_scanned{$var} = 1;
+    
+    foreach my $cond (&variable_conditions ($var))
+    {
 	return 1
 	  unless $cond =~ /^TRUE|FALSE$/;
-      }
+
+	foreach my $val (&variable_value_as_list ($var, $cond, $parent))
+	{
+	    my ($isvar, $subvar) = extract_variable_reference($val);
+	    if ($isvar)
+	    {
+		# Handle a sub variable
+		next if ! defined $subvar;
+		return 1
+		  if variable_conditionally_defined_sub($subvar, $var);
+	    }
+	}
+    }
     return 0;
 }