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Spirik / GEM

Good Enough Menu for Arduino
GNU Lesser General Public License v3.0
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menuItemNext being a wild pointer in certain circumstances #43

Closed shezik closed 2 years ago

shezik commented 2 years ago

I'm working on an ESP32 project where everything GEM-related is dynamically allocated. However LoadProhibited fatal error occurs when menu.drawMenu() is called. Turns out that pointer menuItemNext defined in GEMItem.h is wild and the issue disappears if menuItemNext is initialized with nullptr.

    GEMPage* parentPage = nullptr;  
    GEMPage* linkedPage;  
    GEMItem* menuItemNext = nullptr;  // <- Here
    void (*buttonAction)();

I wonder if this is because that all objects are dynamically allocated or just that I'm retarded (I did not dig too deep into the code). Code can be provided if required. :)

Spirik commented 2 years ago

Good catch!

Yes, by all means menuItemNext should be initialized with nullptr by default. However, this error doesn't trigger during "normal" workflow (e.g. examples that come with GEM) and probably related to dynamic allocation in your case. And indeed the last menu item of the menu page may end up having menuItemNext left as an uninitialized wild pointer. Which is, of course, bad and should be avoided. So I will fix it on the next patch release. Thank you!

Spirik commented 2 years ago

Fix now available in 1.3.4 release. Please check, if this will work for you.

shezik commented 2 years ago

Fix now available in 1.3.4 release. Please check, if this will work for you.

It definitely does. Thank you for being so responsive! :D