From 4732b861f377ee8ff5c7740c171ea6d2b412ad90 Mon Sep 17 00:00:00 2001
From: Joep Vanlier <joep.vanlier@gmail.com>
Date: Fri, 20 Sep 2024 00:09:55 +0200
Subject: [PATCH] ysfx: don't allow making undefined sliders visible

---
 sources/ysfx_api_reaper.cpp | 47 ++++++++++++++++++++-----------------
 tests/ysfx_test_slider.cpp  |  3 +++
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/sources/ysfx_api_reaper.cpp b/sources/ysfx_api_reaper.cpp
index 153ad9c..de58ade 100644
--- a/sources/ysfx_api_reaper.cpp
+++ b/sources/ysfx_api_reaper.cpp
@@ -131,31 +131,34 @@ static EEL_F NSEEL_CGEN_CALL ysfx_api_slider_show(void *opaque, EEL_F *mask_or_s
     ysfx_t *fx = REAPER_GET_INTERFACE(opaque);
     uint32_t slider = ysfx_get_slider_of_var(fx, mask_or_slider_);
 
-    uint8_t group;
-    uint64_t mask;
-    if (slider < ysfx_max_sliders) {
-        group = ysfx_fetch_slider_group_index(slider);
-        mask = ysfx_slider_mask(slider, group);
-    } else {
-        group = 0;
-        mask = ysfx_eel_round<uint64_t>(std::fabs(*mask_or_slider_));
-    }
+    if (ysfx_slider_exists(fx, slider)) {
+        uint8_t group;
+        uint64_t mask;
+        if (slider < ysfx_max_sliders) {
+            group = ysfx_fetch_slider_group_index(slider);
+            mask = ysfx_slider_mask(slider, group);
+        } else {
+            group = 0;
+            mask = ysfx_eel_round<uint64_t>(std::fabs(*mask_or_slider_));
+        }
 
-    if (*value_ >= (EEL_F)+0.5) {
-        // show
-        fx->slider.visible_mask[group] |= mask;
-    }
-    else if (*value_ >= (EEL_F)-0.5) {
-        // hide
-        mask = ~mask;
-        fx->slider.visible_mask[group] &= mask;
-    }
-    else {
-        // toggle
-        mask = fx->slider.visible_mask[group].fetch_xor(mask) ^ mask;
+        if (*value_ >= (EEL_F)+0.5) {
+            // show
+            fx->slider.visible_mask[group] |= mask;
+        }
+        else if (*value_ >= (EEL_F)-0.5) {
+            // hide
+            mask = ~mask;
+            fx->slider.visible_mask[group] &= mask;
+        }
+        else {
+            // toggle
+            mask = fx->slider.visible_mask[group].fetch_xor(mask) ^ mask;
+        }
+        return (EEL_F)mask;
     }
 
-    return (EEL_F)mask;
+    return (EEL_F)0;
 }
 
 static EEL_F NSEEL_CGEN_CALL ysfx_api_midisend(void *opaque, INT_PTR np, EEL_F **parms)
diff --git a/tests/ysfx_test_slider.cpp b/tests/ysfx_test_slider.cpp
index d0d4f7d..1008da5 100644
--- a/tests/ysfx_test_slider.cpp
+++ b/tests/ysfx_test_slider.cpp
@@ -105,6 +105,7 @@ TEST_CASE("slider manipulation", "[sliders]")
             "slider_show(slider5,1);" "\n"
             "slider_show(slider6,-1);" "\n"
             "slider_show(slider254,1);" "\n"
+            "slider_show(8,1);" "\n"
             "slider_show(slider255,-1);" "\n";
 
         scoped_new_dir dir_fx("${root}/Effects");
@@ -136,6 +137,7 @@ TEST_CASE("slider manipulation", "[sliders]")
         REQUIRE(!slider_is_visible(3));
         REQUIRE(!slider_is_visible(4));
         REQUIRE(!slider_is_visible(5));
+        REQUIRE(!slider_is_visible(7));
 
         visible = ysfx_get_slider_visibility(fx.get(), 3);
         REQUIRE(!slider_is_visible(253));
@@ -150,6 +152,7 @@ TEST_CASE("slider manipulation", "[sliders]")
         REQUIRE(!slider_is_visible(3));
         REQUIRE(slider_is_visible(4));
         REQUIRE(slider_is_visible(5));
+        REQUIRE(!slider_is_visible(7));
 
         visible = ysfx_get_slider_visibility(fx.get(), 3);
         REQUIRE(slider_is_visible(253));