A set of minor beta fixes

1. Add a regtest to show FTZ works properly.
2. Don't allow -ve typeins to nan A2bx. Closes surge-synthesizer#5607
3. Deal with command toggle on/off during drag to change states
   even more properly. Closes surge-synthesizer#5606
4. Don't linger hover from Type onto Step Seq Shift.
   Closes surge-synthesizer#5605
5. Formula/Modulator cross-scene tearout works. Closes surge-synthesizer#5590

src/common/Parameter.cpp

@@ -4232,6 +4232,10 @@ bool Parameter::set_value_from_string_onto(const std::string &s, pdata &ontoThis
         ** log2(v/a) = bx
         ** log2(v/a)/b = x;
         */
+        if (nv <= 0 || !std::isfinite(nv))
+        {
+            return false;
+        }
         float res = log2f(nv / displayInfo.a) / displayInfo.b;
 
         if (res < val_min.f || res > val_max.f)

src/surge-testrunner/UnitTestsDSP.cpp

@@ -17,6 +17,7 @@
 #include <complex>
 
 #include "LanczosResampler.h"
+#include "CPUFeatures.h"
 
 using namespace Surge::Test;
 
@@ -1054,4 +1055,28 @@ TEST_CASE("Wavehaper LUT", "[dsp]")
             }
         }
     }
+}
+
+TEST_CASE("FTZ", "[dsp]")
+{
+    auto g = Surge::CPUFeatures::FPUStateGuard();
+
+    unsigned char min_float[4] = {0x00, 0x00, 0x80, 0x00};
+    float f_min;
+    memcpy(&f_min, min_float, 4);
+    REQUIRE(f_min != 0.f);
+
+    unsigned char res_float[4];
+    for (int i = 0; i < 100; ++i)
+    {
+        // don't let the compiler optimize me away!
+        auto r = 1.0 / (fabs(rand() % 10) + 1.1); // a number < 1
+        float ftz_float = f_min * r;
+        memcpy(res_float, &ftz_float, 4);
+        for (int i = 0; i < 4; ++i)
+        {
+            REQUIRE(res_float[i] == 0);
+        }
+        REQUIRE(ftz_float == 0.f);
+    }
 }

src/surge-xt/gui/SurgeGUIEditor.h

@@ -371,7 +371,11 @@ class SurgeGUIEditor : public Surge::GUI::IComponentTagValue::Listener,
     }
 
     Surge::Overlays::OverlayWrapper *getOverlayWrapperIfOpen(OverlayTags tag);
-    void refreshOverlayWithOpenClose(OverlayTags tag);
+    void refreshOverlayWithOpenClose(OverlayTags tag)
+    {
+        refreshAndMorphOverlayWithOpenClose(tag, tag);
+    }
+    void refreshAndMorphOverlayWithOpenClose(OverlayTags tag, OverlayTags newTag);
 
     void updateWaveshaperOverlay(); // this is the only overlay which updates from patch values
 

src/surge-xt/gui/SurgeGUIEditorOverlays.cpp

@@ -573,7 +573,7 @@ void SurgeGUIEditor::rezoomOverlays()
     }
 }
 
-void SurgeGUIEditor::refreshOverlayWithOpenClose(OverlayTags tag)
+void SurgeGUIEditor::refreshAndMorphOverlayWithOpenClose(OverlayTags tag, OverlayTags newTag)
 {
     if (!isAnyOverlayPresent(tag))
         return;
@@ -590,7 +590,7 @@ void SurgeGUIEditor::refreshOverlayWithOpenClose(OverlayTags tag)
      * Some editors can do better than a forced open-clsoe
      */
     bool couldRefresh = true;
-    switch (tag)
+    switch (newTag)
     {
     case TUNING_EDITOR:
     {
@@ -624,10 +624,10 @@ void SurgeGUIEditor::refreshOverlayWithOpenClose(OverlayTags tag)
     if (!couldRefresh)
     {
         closeOverlay(tag);
-        showOverlay(tag);
+        showOverlay(newTag);
         if (to)
         {
-            olw = getOverlayWrapperIfOpen(tag);
+            olw = getOverlayWrapperIfOpen(newTag);
             if (olw)
                 olw->doTearOut(tol);
         }

src/surge-xt/gui/SurgeGUIEditorValueCallbacks.cpp

@@ -278,35 +278,37 @@ void SurgeGUIEditor::changeSelectedScene(int value)
     synth->release_if_latched[synth->storage.getPatch().scene_active.val.i] = true;
     synth->storage.getPatch().scene_active.val.i = current_scene;
 
-    if (isAnyOverlayPresent(MSEG_EDITOR))
+    bool hasMSEG = isAnyOverlayPresent(MSEG_EDITOR);
+    bool hasForm = isAnyOverlayPresent(FORMULA_EDITOR);
+
+    if (hasForm || hasMSEG)
     {
         auto ld = &(synth->storage.getPatch()
                         .scene[current_scene]
                         .lfo[modsource_editor[current_scene] - ms_lfo1]);
 
-        if (ld->shape.val.i == lt_mseg)
+        if (ld->shape.val.i == lt_mseg && hasMSEG)
         {
             refreshOverlayWithOpenClose(SurgeGUIEditor::MSEG_EDITOR);
         }
-        else
+        else if (ld->shape.val.i == lt_formula && hasForm)
         {
-            closeOverlay(SurgeGUIEditor::MSEG_EDITOR);
+            refreshOverlayWithOpenClose(SurgeGUIEditor::FORMULA_EDITOR);
         }
-    }
-
-    if (isAnyOverlayPresent(FORMULA_EDITOR))
-    {
-        auto ld = &(synth->storage.getPatch()
-                        .scene[current_scene]
-                        .lfo[modsource_editor[current_scene] - ms_lfo1]);
-
-        if (ld->shape.val.i == lt_formula)
+        else if (ld->shape.val.i == lt_mseg && hasForm)
         {
-            refreshOverlayWithOpenClose(SurgeGUIEditor::FORMULA_EDITOR);
+            refreshAndMorphOverlayWithOpenClose(FORMULA_EDITOR, MSEG_EDITOR);
+        }
+        else if (ld->shape.val.i == lt_formula && hasMSEG)
+        {
+            refreshAndMorphOverlayWithOpenClose(MSEG_EDITOR, FORMULA_EDITOR);
         }
         else
         {
-            closeOverlay(SurgeGUIEditor::FORMULA_EDITOR);
+            if (hasForm)
+                closeOverlay(SurgeGUIEditor::FORMULA_EDITOR);
+            if (hasMSEG)
+                closeOverlay(SurgeGUIEditor::MSEG_EDITOR);
         }
     }
 

src/surge-xt/gui/widgets/LFOAndStepDisplay.cpp

@@ -1528,6 +1528,8 @@ void LFOAndStepDisplay::mouseMove(const juce::MouseEvent &event)
         }
     }
 
+    // reset for the step hover
+    nextHover = -1;
     if (ss_shift_left.contains(event.position))
     {
         nextHover = 0;
@@ -1670,6 +1672,12 @@ void LFOAndStepDisplay::mouseDrag(const juce::MouseEvent &event)
             setStepToDefault(event);
             return;
         }
+        else
+        {
+            dragMode = VALUES;
+            setStepValue(event);
+            return;
+        }
         break;
     }
     case TRIGGERS:
@@ -1700,6 +1708,7 @@ void LFOAndStepDisplay::mouseDrag(const juce::MouseEvent &event)
     {
         if (event.mods.isCommandDown())
         {
+            dragMode = RESET_VALUE;
             setStepToDefault(event);
         }
         else