Scale Dependent Visibility on layer wrong on scale interval edges in EPSG:25832

[chau-intl]

What is the bug or the crash?

I have two layers, L1 and L2, and both has Scale Dependent Visibility (Layer Properties / Rendering) enabled:

• L1 has Maximum (inclusive) set to 1:1 and has Minimum (exclusive) set to 1:100.
• L2 has Maximum (inclusive) set to 1:100 and has Minimum (exclusive) set to 1:1,000.

When setting the zoom level of QGIS to exactly 1:100 both L1 and L2 are visible. I would expect L1 to be invisible (since it has exclusive on Minimum) and L2 to be visible (since it has inclusive on Maximum).

I didn't submit this ticket just because of issues with scale 1:100. I see the same issue at scale 1:10,000, 1:25,000, 1:100,000, 1:250,000 and 1:1,000,000 but not at scale 1:50,000, 1:500,000 and 1:5,000,000.

Steps to reproduce the issue

Add two layers and set the scale dependent visibility of both layers according to the bug-description.

Versions

3.34.8, 3.38.0, 3.39 (67e0563) - all on Windows 10.

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

Looking briefly at the code I see this:

QGIS/src/core/qgis.cpp

Line 56 in 9e47ca4

const double Qgis::SCALE_PRECISION = 0.9999999999;

QGIS/src/core/qgsmaplayer.cpp

Lines 1147 to 1151 in 9e47ca4

	QGIS_PROTECT_QOBJECT_THREAD_ACCESS_NON_FATAL
	return !mScaleBasedVisibility ||
	( ( mMinScale == 0 || mMinScale * Qgis::SCALE_PRECISION < scale )
	&& ( mMaxScale == 0 || scale < mMaxScale ) );

Could the SCALE_PRECISION be the reason that both layers are rendered at exactly 1:100 in EPSG:25832?

[gacarrillor]

@chau-intl, this should be solved for QGIS 3.40, which will be available on 25th October.
Feel free to reopen if you still find issues.

[chau-intl]

@gacarrillor, I have just tested the QGIS nightlies and in my use cases now it works. Thanks a lot for looking into this!

[gacarrillor]

Great! Thanks for reporting.