Mesa (master): Revert "mesa: do not trigger _NEW_TEXTURE_STATE in glActiveTexture()"

[Samuel Pitoiset]

Module: Mesa
Branch: master
Commit: f02f1ad13fa4123986d17a5d04b0e2831c3a7091
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=f02f1ad13fa4123986d17a5d04b0e2831c3a7091

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Wed Mar 14 09:46:33 2018 +0100

Revert "mesa: do not trigger _NEW_TEXTURE_STATE in glActiveTexture()"

This reverts commit f314a532fdc7af8381586144d2631d9968331f05.

This appears to introduce some blinking textures in UT2004. Not
sure exactly what's the root cause because we don't have much
information about the issue.

Anyway, this was just a micro optimization that actually breaks,
at least, one app almost one year later.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105436
Cc: <mesa-stable at lists.freedesktop.org>
Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

---

 src/mesa/main/texstate.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/mesa/main/texstate.c b/src/mesa/main/texstate.c
index f9f50a3005..9b64b64ae5 100644
--- a/src/mesa/main/texstate.c
+++ b/src/mesa/main/texstate.c
@@ -310,6 +310,19 @@ active_texture(GLenum texture, bool no_error)
       }
    }
 
+
+   /* The below flush call seems useless because
+    * gl_context::Texture::CurrentUnit is not used by
+    * _mesa_update_texture_state() and friends.
+    *
+    * However removing the flush
+    * introduced some blinking textures in UT2004. More investigation is
+    * needed to find the root cause.
+    *
+    * https://bugs.freedesktop.org/show_bug.cgi?id=105436
+    */
+   FLUSH_VERTICES(ctx, _NEW_TEXTURE_STATE);
+
    ctx->Texture.CurrentUnit = texUnit;
    if (ctx->Transform.MatrixMode == GL_TEXTURE) {
       /* update current stack pointer */