Fix situation in which we don't get an full result from terminal.

Don't crash if the color information is not complete yet.
Can happen in particular on slow ssh connections.

Author: hzeller

src/term-query.cc

@@ -202,7 +202,7 @@ const char *QueryBackgroundColor() {
             // We might've gotten some spurious bytes in the beginning from
             // keypresses, so find where the color starts.
             const char *found = find_str(data, len, "rgb:");
-            return strchr(found, '\\') ? found : nullptr;
+            return found && strchr(found, '\\') ? found : nullptr;
         });
 
     if (!start_color) return nullptr;