Modifiers: Change softbody fuzzy default value

Set fuzzy=1 when softbody modifier is added. As of now, value is 0, this
raises concern of division by zero so bump it to 1.
Updated `softbody_test.blend` to fix the failing test.
Resolves #137849

Pull Request: https://projects.blender.org/blender/blender/pulls/137878

source/blender/blenkernel/BKE_blender_version.h

@@ -27,7 +27,7 @@
 
 /* Blender file format version. */
 #define BLENDER_FILE_VERSION BLENDER_VERSION
-#define BLENDER_FILE_SUBVERSION 82
+#define BLENDER_FILE_SUBVERSION 83
 
 /* 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/blenkernel/intern/softbody.cc

@@ -3140,6 +3140,7 @@ SoftBody *sbNew()
   sb->maxloops = 300;
 
   sb->choke = 3;
+  sb->fuzzyness = 1;
   sb_new_scratch(sb);
   /* TODO: backward file compatibility should set `sb->shearstiff = 1.0f` while reading old files.
    */

source/blender/blenloader/intern/versioning_450.cc

@@ -15,6 +15,7 @@
 #include "DNA_defaults.h"
 #include "DNA_light_types.h"
 #include "DNA_mesh_types.h"
+#include "DNA_object_force_types.h"
 #include "DNA_sequence_types.h"
 
 #include "BLI_listbase.h"
@@ -6094,6 +6095,13 @@ void blo_do_versions_450(FileData * /*fd*/, Library * /*lib*/, Main *bmain)
     }
   }
 
+  if (!MAIN_VERSION_FILE_ATLEAST(bmain, 405, 83)) {
+    LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+      if (ob->soft) {
+        ob->soft->fuzzyness = std::max<int>(1, ob->soft->fuzzyness);
+      }
+    }
+  }
   /* Always run this versioning (keep at the bottom of the function). Meshes are written with the
    * legacy format which always needs to be converted to the new format on file load. To be moved
    * to a subversion check in 5.0. */