From 6cedbc33c05fc430e85d7e0dc765b07881ee78c2 Mon Sep 17 00:00:00 2001
From: Emilie Burgun <emilie@shadamethyst.xyz>
Date: Tue, 7 Jan 2025 17:59:13 +0100
Subject: [PATCH 1/2] Fix load_context_module triggering unreachable code in
 unify_atom

---
 src/machine/dispatch.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/machine/dispatch.rs b/src/machine/dispatch.rs
index f77f7f0f..635de289 100644
--- a/src/machine/dispatch.rs
+++ b/src/machine/dispatch.rs
@@ -4812,11 +4812,11 @@ impl Machine {
                         step_or_fail!(self, self.machine_st.p = self.machine_st.cp);
                     }
                     &Instruction::CallLoadContextModule => {
-                        self.load_context_module(self.machine_st.registers[1]);
+                        self.load_context_module(self.deref_register(1));
                         step_or_fail!(self, self.machine_st.p += 1);
                     }
                     &Instruction::ExecuteLoadContextModule => {
-                        self.load_context_module(self.machine_st.registers[1]);
+                        self.load_context_module(self.deref_register(1));
                         step_or_fail!(self, self.machine_st.p = self.machine_st.cp);
                     }
                     &Instruction::CallLoadContextStream => {

From eff094cc2906f830b1a8c306d5fc9aa34b893bbc Mon Sep 17 00:00:00 2001
From: Emilie Burgun <emilie@shadamethyst.xyz>
Date: Tue, 7 Jan 2025 18:10:50 +0100
Subject: [PATCH 2/2] Add tests for PR #2756

---
 tests-pl/load-context-unreachable.pl | 1 +
 tests/scryer/issues.rs               | 8 ++++++++
 2 files changed, 9 insertions(+)
 create mode 100644 tests-pl/load-context-unreachable.pl

diff --git a/tests-pl/load-context-unreachable.pl b/tests-pl/load-context-unreachable.pl
new file mode 100644
index 00000000..5a0f2782
--- /dev/null
+++ b/tests-pl/load-context-unreachable.pl
@@ -0,0 +1 @@
+:- initialization((M = user, loader:load_context(M))).
diff --git a/tests/scryer/issues.rs b/tests/scryer/issues.rs
index de318708..207c4909 100644
--- a/tests/scryer/issues.rs
+++ b/tests/scryer/issues.rs
@@ -25,3 +25,11 @@ fn issue2588_load_html() {
 fn call_qualification() {
     load_module_test("tests-pl/issue2361-call-qualified.pl", "");
 }
+
+// PR #2756: ensures that calling load_context with a bound variable doesn't trigger unreachable!()
+#[serial]
+#[test]
+#[cfg_attr(miri, ignore = "it takes too long to run")]
+fn load_context_unreachable() {
+    load_module_test("tests-pl/load-context-unreachable.pl", "");
+}