2010-11-28  Paul Smith  <psmith@gnu.org>

	* read.c (record_target_var): Don't reset v if it's the same as

	the global version.  Fixes Savannah bug #31743.

--- a/doc/make.texi

+++ b/doc/make.texi

@@ -4295,10 +4295,10 @@ recipes, is propagated to the subsystem.@refill

 Variable values of the top-level @code{make} can be passed to the

 sub-@code{make} through the environment by explicit request.  These

-variables are defined in the sub-@code{make} as defaults, but do not

-override what is specified in the makefile used by the sub-@code{make}

-makefile unless you use the @samp{-e} switch (@pxref{Options Summary,

-,Summary of Options}).@refill

+variables are defined in the sub-@code{make} as defaults, but they do

+not override variables defined in the makefile used by

+the sub-@code{make} unless you use the @samp{-e} switch (@pxref{Options

+Summary, ,Summary of Options}).@refill

 To pass down, or @dfn{export}, a variable, @code{make} adds the

 variable and its value to the environment for running each line of the

--- a/read.c

+++ b/read.c

@@ -1802,7 +1802,8 @@ record_target_var (struct nameseq *filenames, char *defn,

           int len = strlen(v->name);

           gv = lookup_variable (v->name, len);

-          if (gv && (gv->origin == o_env_override || gv->origin == o_command))

+          if (gv && v != gv

+              && (gv->origin == o_env_override || gv->origin == o_command))

             {

               if (v->value != 0)

                 free (v->value);

--- a/tests/scripts/features/targetvars

+++ b/tests/scripts/features/targetvars

@@ -237,6 +237,16 @@ a: ; @echo "$(FOO)"

 run_make_test(undef, 'FOO=C', "C f1\n");

+# TEST #19: Conditional variables with command-line settings

+

+run_make_test('

+a: FOO ?= f1

+a: ; @echo "$(FOO)"

+',

+              '', "f1\n");

+

+run_make_test(undef, 'FOO=C', "C\n");

+

 # TEST #20: Check for continuation after semicolons

 run_make_test(q!