fix: set index and value to 0 for array_get with predicate

compiler/noirc_evaluator/src/ssa/acir_gen/mod.rs

@@ -282,7 +282,7 @@
         brillig: &Brillig,
     ) -> Result<(Vec<GeneratedAcir>, Vec<BrilligBytecode>), RuntimeError> {
         let mut acirs = Vec::new();
         // TODO: can we parallelise this?
         let mut shared_context = SharedContext::default();
         for function in self.functions.values() {
             let context = Context::new(&mut shared_context);
@@ -1200,7 +1200,14 @@
             !res_typ.contains_slice_element(),
             "ICE: Nested slice result found during ACIR generation"
         );
-        let value = self.array_get_value(&res_typ, block_id, &mut var_index)?;
+        let mut value = self.array_get_value(&res_typ, block_id, &mut var_index)?;
+        if let AcirValue::Var(value_var, typ) = value {
+            // Set the value to 0 if current_side_effects is 0, to ensure it fits in any value type
+            value = AcirValue::Var(
+                self.acir_context.mul_var(value_var, self.current_side_effects_enabled_var)?,
+                typ,
+            );
+        }
 
         self.define_result(dfg, instruction, value.clone());
 

test_programs/execution_success/regression_struct_array_conditional/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "regression_struct_array_conditional"
+version = "0.1.0"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/execution_success/regression_struct_array_conditional/Prover.toml

@@ -0,0 +1,18 @@
+y = 1
+z = 1
+
+[[x]]
+value =  "0x23de33be058ce5504e1ade738db8bdacfe268fa9dbde777092bf1d38519bdf59"
+counter = "10"
+dummy = "0"
+
+[[x]]
+value = "3"
+counter = "2"
+dummy = "0"
+
+[[x]]
+value = "2"
+counter = "0"
+dummy = "0"
+

test_programs/execution_success/regression_struct_array_conditional/src/main.nr

@@ -0,0 +1,11 @@
+struct foo {
+    value: Field,
+    counter: u8,
+    dummy: u8,
+}
+fn main(x: [foo; 3], y: u32, z: u32) -> pub u8 {
+    if z == 0 {
+        assert(y as u8 < x[y].counter);
+    }
+    x[0].counter
+}