Fix: Add versioning for recently added curves sculpt radius interpolation

- Turn on radius interpolation by default for old files.
- Set the fallback radius to 0.01 for old files.

source/blender/blenkernel/BKE_blender_version.h

@@ -29,7 +29,7 @@ extern "C" {
 
 /* Blender file format version. */
 #define BLENDER_FILE_VERSION BLENDER_VERSION
-#define BLENDER_FILE_SUBVERSION 6
+#define BLENDER_FILE_SUBVERSION 7
 
 /* Minimum Blender version that supports reading file written with the current
  * version. Older Blender versions will test this and cancel loading the file, showing a warning to

source/blender/blenloader/intern/versioning_400.cc

@@ -2966,6 +2966,15 @@ void blo_do_versions_400(FileData *fd, Library * /*lib*/, Main *bmain)
     }
   }
 
+  if (!MAIN_VERSION_FILE_ATLEAST(bmain, 402, 6)) {
+    LISTBASE_FOREACH (Brush *, brush, &bmain->brushes) {
+      if (BrushCurvesSculptSettings *settings = brush->curves_sculpt_settings) {
+        settings->flag |= BRUSH_CURVES_SCULPT_FLAG_INTERPOLATE_RADIUS;
+        settings->curve_radius = 0.01f;
+      }
+    }
+  }
+
   /**
    * Always bump subversion in BKE_blender_version.h when adding versioning
    * code here, and wrap it inside a MAIN_VERSION_FILE_ATLEAST check.