Index: source/Host/common/Editline.cpp
===================================================================
--- source/Host/common/Editline.cpp
+++ source/Host/common/Editline.cpp
@@ -1215,9 +1215,11 @@
   if (m_editline != nullptr) {
     el_resize(m_editline);
     int columns;
-    // Despite the man page claiming non-zero indicates success, it's actually
-    // zero
-    if (el_get(m_editline, EL_GETTC, "co", &columns) == 0) {
+    // Mac man page claims non-zero indicates success, but it's actually
+    // zero. Additionally, all manpages document the varargs part of this
+    // function as (const char *name, void *value), but in reality the source
+    // code expects the vararg list to be terminated by a null pointer.
+    if (el_get(m_editline, EL_GETTC, "co", &columns, nullptr) == 0) {
       m_terminal_width = columns;
       if (m_current_line_rows != -1) {
         const LineInfoW *info = el_wline(m_editline);