Bug in change plugin attributes

[tbeu]

There is a bug in the change plugin attributes dialog of the content plugin interface of Total Commander 7.04a. The bug is in the parameters of the ContentSetValue() function when called a second time with more than one attribute.

For demonstration the open source JPG comment, EXIF and IPTC metadata content plugin Vs 2.1.4.0 is used.

The declaration of ContentSetValue() looks like

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int ContentSetValue(char* FileName, int FieldIndex, int UnitIndex, int FieldType, void* FieldValue, int flags);

When the change attributes dialog is called the first time with the settings from Image: http://tbeu.de/forum/ca1.png ContentSetValue() is called three times and every thing is fine.

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ContentSetValue("C:\\file.jpg", 21, 0, 8, 0x00c2dca4, 1)
ContentSetValue("C:\\file.jpg", 23, 0, 8, 0x00c2e71c, 2)
ContentSetValue(NULL, -1, -1, 0, 0x00000000, 0)

When the change attributes dialog is then called a second time with the new settings from Image: http://tbeu.de/forum/ca2.png ContentSetValue() is called four times, however the field index of the second call is zero instead of 23 as before.

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ContentSetValue("C:\\file.jpg", 21, 0, 8, 0x00c28918, 1)
ContentSetValue("C:\\file.jpg", 0 /* bug: value 23 is expected */, 0, 8, 0x00bef978, 0)
ContentSetValue("C:\\file.jpg", 3, 0, 8, 0x00bf07b8, 2)
ContentSetValue(NULL, -1, -1, 0, 0x00000000, 0)

As result the wrong attribute is changed!

[ghisler(Author)]

I will try to reproduce it, thanks. What do you mean with "a second time"? Do you mean that the problem doesn't occur when you use the attributes dialog for the first time after starting TC?

[tbeu]

What do you mean with "a second time"?

Right, if the change attributes dialog is called the first time after starting TC it works as expected. If the same scenario is then repeated a second time (of the same instance of TC) the plugin parameters are wrong as stated above.

[ghisler(Author)]

I can confirm the problem with the referenced plugin. It's indeed a bug: The change attribute dialog currently supports only a maximum of 20 changeable properties per plugin. The plugin can have more properties, but only 20 of them may be changeable. I changed this from 20 to 100 sometimes, but forgot to increase the size of the reference array which maps the changeable property numbers to all available properties. Therefore an overlap can occur when changing more than one property at a time. I will fix it in TC 7.5 (and Tc 7.04c or so).

[tbeu]

OK, then the current workaround is to change only one attribute per time if there are in total more than 20 changeable attributes of the plugin.

[tbeu]

Fixed in TC 7.5PB1. Thank you!

However, there might be plugins with more than 100 changeable fields.

[ghisler(Author)]

Thanks! That should be no problem, though, because TC will correctly limit them to 100 now.