diff --git a/src/input_handler.cc b/src/input_handler.cc
index 9d81f711..5800a6a0 100644
--- a/src/input_handler.cc
+++ b/src/input_handler.cc
@@ -1191,7 +1191,7 @@ public:
         }
     }
 
-    void on_key(Key key, bool) override
+    void on_key(Key key, bool synthesized) override
     {
         auto& buffer = context().buffer();
 
@@ -1289,22 +1289,13 @@ public:
                 }, "enter register name", register_doc.str());
             update_completions = false;
         }
-        else if (key == ctrl('n'))
+        else if (key == ctrl('n') or key == ctrl('p') or key.modifiers == Key::Modifiers::MenuSelect)
         {
-            last_insert().keys.pop_back();
-            m_completer.select(1, true, last_insert().keys);
-            update_completions = false;
-        }
-        else if (key == ctrl('p'))
-        {
-            last_insert().keys.pop_back();
-            m_completer.select(-1, true, last_insert().keys);
-            update_completions = false;
-        }
-        else if (key.modifiers == Key::Modifiers::MenuSelect)
-        {
-            last_insert().keys.pop_back();
-            m_completer.select(key.key, false, last_insert().keys);
+            if (not synthesized)
+                last_insert().keys.pop_back();
+            bool relative = key.modifiers != Key::Modifiers::MenuSelect;
+            int index = relative ? (key == ctrl('n') ? 1 : -1) : key.key;
+            m_completer.select(index, relative, last_insert().keys);
             update_completions = false;
         }
         else if (key == ctrl('x'))
diff --git a/test/regression/5120-double-free-or-corruption-crash/cmd b/test/regression/5120-double-free-or-corruption-crash/cmd
new file mode 100644
index 00000000..3076ee65
--- /dev/null
+++ b/test/regression/5120-double-free-or-corruption-crash/cmd
@@ -0,0 +1 @@
+ggQm*nWd<a-l>d<a-d>n<a-c>\fo<c-n>{<c-r>"}<esc>Q8q
diff --git a/test/regression/5120-double-free-or-corruption-crash/in b/test/regression/5120-double-free-or-corruption-crash/in
new file mode 100644
index 00000000..ca91936a
--- /dev/null
+++ b/test/regression/5120-double-free-or-corruption-crash/in
@@ -0,0 +1,40 @@
+Lorem ipsum dolor sit amet consectetur adipisicing elit[1]. Maxime mollitia,
+molestiae quas vel sint commodi[2] repudiandae consequuntur voluptatum laborum
+numquam blanditiis harum quisquam eius sed odit fugiat iusto fuga praesentium
+optio, eaque rerum![3] Provident similique accusantium nemo autem. Veritatis
+obcaecati tenetur iure eius earum ut molestias architecto voluptate aliquam
+nihil,[4] eveniet aliquid culpa officia aut! Impedit sit sunt quaerat, odit,
+tenetur error, harum nesciunt ipsum debitis quas aliquid. Reprehenderit,
+quia. Quo neque error repudiandae fuga? Ipsa laudantium molestias eos 
+sapiente officiis modi at sunt excepturi expedita sint? Sed quibusdam
+recusandae alias error harum maxime adipisci amet laborum[5]. Perspiciatis 
+minima nesciunt dolorem! Officiis iure rerum voluptates a cumque velit 
+quibusdam sed amet tempora[6]. Sit laborum ab, eius fugit doloribus tenetur 
+fugiat, temporibus enim commodi iusto libero magni deleniti quod quam 
+consequuntur! Commodi minima excepturi repudiandae velit hic maxime
+doloremque[7]. Quaerat provident commodi consectetur veniam similique ad 
+earum omnis ipsum saepe, voluptas, hic voluptates pariatur est explicabo 
+fugiat, dolorum eligendi quam cupiditate excepturi mollitia maiores labore 
+suscipit quas? Nulla, placeat[8]. Voluptatem quaerat non architecto ab laudantium
+modi minima sunt esse temporibus sint culpa, recusandae aliquam numquam 
+totam ratione voluptas quod exercitationem fuga[9]. Possimus quis earum veniam 
+quasi aliquam eligendi, placeat qui corporis!
+
+
+[1] This is the first footnote.
+
+[2] This is the second footnote.
+
+[3] This is the third footnote.
+
+[4] This is the fourth footnote.
+
+[5] This is the fifth footnote.
+
+[6] This is the sixth footnote.
+
+[7] This is the seventh footnote.
+
+[8] This is the eighth footnote.
+
+[9] This is the Ninth footnote.