5 files changed, 36 insertions, 0 deletions
diff --git a/source/blender/blenkernel/BKE_blender_version.h b/source/blender/blenkernel/BKE_blender_version.h
index 3df09d08814..c340e1f1ff7 100644
--- a/source/blender/blenkernel/BKE_blender_version.h
+++ b/source/blender/blenkernel/BKE_blender_version.h
@@ -50,6 +50,9 @@ extern "C" {
 /** User readable version string. */
 const char *BKE_blender_version_string(void);
 
+/* Returns true when version cycle is alpha, otherwise (beta, rc) returns false. */
+bool BKE_blender_version_is_alpha(void);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index e8aa13a8beb..af502d30145 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -135,6 +135,12 @@ const char *BKE_blender_version_string(void)
   return blender_version_string;
 }
 
+bool BKE_blender_version_is_alpha(void)
+{
+  static bool is_alpha = STREQ(STRINGIFY(BLENDER_VERSION_CYCLE), "alpha");
+  return is_alpha;
+}
+
 void BKE_blender_globals_init(void)
 {
   blender_version_init();
diff --git a/source/blender/blenloader/BLO_readfile.h b/source/blender/blenloader/BLO_readfile.h
index 97c77ed2e19..580c833d8dc 100644
--- a/source/blender/blenloader/BLO_readfile.h
+++ b/source/blender/blenloader/BLO_readfile.h
@@ -186,6 +186,9 @@ void BLO_update_defaults_workspace(struct WorkSpace *workspace, const char *app_
 /* Version patch user preferences. */
 void BLO_version_defaults_userpref_blend(struct Main *mainvar, struct UserDef *userdef);
 
+/* Disable unwanted experimental feature settings on startup. */
+void BLO_sanitize_experimental_features_userpref_blend(struct UserDef *userdef);
+
 struct BlendThumbnail *BLO_thumbnail_from_file(const char *filepath);
 
 /* datafiles (generated theme) */
diff --git a/source/blender/blenloader/intern/versioning_userdef.c b/source/blender/blenloader/intern/versioning_userdef.c
index 50e3b375166..ec631eb64f3 100644
--- a/source/blender/blenloader/intern/versioning_userdef.c
+++ b/source/blender/blenloader/intern/versioning_userdef.c
@@ -38,6 +38,7 @@
 #include "DNA_windowmanager_types.h"
 
 #include "BKE_addon.h"
+#include "BKE_blender_version.h"
 #include "BKE_colorband.h"
 #include "BKE_idprop.h"
 #include "BKE_keyconfig.h"
@@ -784,4 +785,23 @@ void BLO_version_defaults_userpref_blend(Main *bmain, UserDef *userdef)
 #undef USER_VERSION_ATLEAST
 }
 
+void BLO_sanitize_experimental_features_userpref_blend(UserDef *userdef)
+{
+  /* User preference experimental settings are only supported in alpha builds.
+   * This prevents users corrupting data and relying on API that may change.
+   *
+   * If user preferences are saved this will be stored in disk as expected.
+   * This only starts to take effect when there is a release branch (on beta).
+   *
+   * At that time master already has its version bumped so its user preferences
+   * are not touched by these settings. */
+
+  if (BKE_blender_version_is_alpha()) {
+    return;
+  }
+  userdef->experimental.use_new_particle_system = false;
+  userdef->experimental.use_new_hair_type = false;
+  userdef->experimental.use_sculpt_vertex_colors = false;
+}
+
 #undef USER_LMOUSESELECT
diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index 286cb1571bd..d19c677efb4 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -44,6 +44,8 @@
 
 #include "BLI_utildefines.h"
 
+#include "BLO_readfile.h"
+
 #include "BKE_animsys.h"
 #include "BKE_context.h"
 #include "BKE_idprop.h"
@@ -6818,6 +6820,8 @@ void UI_init_userdef(Main *bmain)
   /* fix saved themes */
   init_userdef_do_versions(bmain);
   uiStyleInit();
+
+  BLO_sanitize_experimental_features_userpref_blend(&U);
 }
 
 void UI_reinit_font(void)