mesa: use _bfc0 instead of _col0 when building back face lighting.

cherry-picked from master: 4550b0562d5b59890fccb0e7eb0dbef967d1ccf9

diff --git a/src/mesa/main/ffvertex_prog.c b/src/mesa/main/ffvertex_prog.c
index dff4306322d70dabccc054cb8fabfebe376d69d7..9ac8328ef0e694ec32ebd53a07b13d4eb92b9425 100644 (file)
--- a/src/mesa/main/ffvertex_prog.c
+++ b/src/mesa/main/ffvertex_prog.c
@@ -1308,14 +1308,13 @@ static void build_lighting( struct tnl_program *p )
             }
             else if (!p->state->material_shininess_is_zero) {
                emit_op1(p, OPCODE_LIT, lit, 0, dots);
-               emit_op2(p, OPCODE_ADD, _col0, 0, ambient, _col0);
+               emit_op2(p, OPCODE_ADD, _bfc0, 0, ambient, _bfc0);
             } 
             else {
                emit_degenerate_lit(p, lit, dots);
-               emit_op2(p, OPCODE_ADD, _col0, 0, ambient, _col0);
+               emit_op2(p, OPCODE_ADD, _bfc0, 0, ambient, _bfc0);
             }
 
-           emit_op2(p, OPCODE_ADD, _bfc0, 0, ambient, _bfc0);
            emit_op3(p, OPCODE_MAD, res0, mask0, swizzle1(lit,Y), diffuse, _bfc0);
            emit_op3(p, OPCODE_MAD, res1, mask1, swizzle1(lit,Z), specular, _bfc1);