Adapt to changes in private headers Qt v6.9

[palinek]

fixes #310

[tsujan]

GTM.

We may need a point release before Qt 6.9 comes out.

[tsujan]

Unfortunately, this breaks our icon engine.

This is a desktop file in pcmanfm-qt's thumbnail view, with a 128-px size, and with libqtxdg 4.1.0:

And the same file with this patch:

The desktop file has Icon=emblem-music-symbolic, which is a 16-px SVG icon belonging to Breeze. Without the patch, it's correctly replaced by emblem-music from my icon set (according to our old rule: "give priority to the set, and only if not found, go to the inherited sets"); with the patch, it's taken from Breeze, which is inherited.

Without the patch, it has the correct size (128); with the patch, its size is 16 px.

EDIT: See "EDIT" in my next comment.

[tsujan]

Solved the size problem by replacing

libqtxdg/src/xdgiconloader/xdgiconloader.cpp

Lines 740 to 741 in 1605b7d

	if (dir.type == QIconDirInfo::Scalable || dynamic_cast<ScalableEntry *>(entry))
	return size;

with

        if (dir.type == QIconDirInfo::Scalable
            || dynamic_cast<ScalableEntry *>(entry)
            || dynamic_cast<ScalableFollowsColorEntry *>(entry)) {
            return size;
        }

But the path problem still exists.

EDIT:
Please forget about path. I was mistaken; it was the same before (I'd changed the Icon= line in the above screenshot for testing).

[tsujan]

Isn't it better to put the above changes inside #if (QT_VERSION >= QT_VERSION_CHECK(6,8,0))? We still support Qt 6.6.

EDIT: Never mind; Qt 6.6 will be OK with this.