Fix display of complex local data types in GDB-MI

* lisp/progmodes/gdb-mi.el (gdb-locals-handler-custom): If a
variable has no value, display "<complex data type>" as a
placeholder, instead of a confusing "nil".  (Bug#21438)

1 files changed, 2 insertions, 0 deletions

diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index 1eff62c5acf..3860c81065d 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -4038,6 +4038,8 @@ member."
       (let ((name (bindat-get-field local 'name))
             (value (bindat-get-field local 'value))
             (type (bindat-get-field local 'type)))
+        (when (not value)
+          (setq value "<complex data type>"))
         (if (or (not value)
                 (string-match "\\0x" value))
             (add-text-properties 0 (length name)