Added, Errors and Warnings window: most of warnings/errors related to (G)ZDoom text lump parsing can now be double-clicked to show warning/error source in the Script Editor.
Fixed: some map format conversion errors were never displayed, because errors list was cleared after performing map conversion.
Fixed: 3d floor indicators in 2D modes were not updated after leaving Visual mode.
Fixed: some UDMF-only interface buttons were never removed after converting map format from UDMF.

Added, Script Editor: MENUDEF and SBARINFO files/lumps are now shown in the Resources list.
Fixed, ACS handling: fixed a crash when trying to parse an #include file, when specified path was absolute.

Added, Script Editor: added "Script Navigator" tab. It shows and allows to open text resources loaded by the editor.
WARNING: because of the large amount of added/modified code, bugs are possible, so backup your resources, save often and report bugs.

Added, Game configurations, ZDoom: Ambient sound things (14001 - 14064) were missing arguments definitions.
Fixed, Make Sectors mode: in some cases sector shape detection logic returned incorrect shape, or no shape at all.

Fixed, Things mode: fixed a crash when deleting Light/Ambient Sound things when "Show Dynamic Light Radii" / "Show Ambient Sound Radii" settings were enabled.
Fixed: WAD lump index was not appended to lump name when reporting errors during ZDoom text lumps parsing.

Fixed, Draw Rectangle mode: fixed a crash caused by incorrectly changing text labels array when accepting the drawing.
Fixed, "Check unknown ACS scripts" error check: named scripts check was performed incorrectly causing it to fail on script names containing uppercase letters.

Fixed, Visual mode, UDMF: "lightfloor" sector property was not applied when calculating thing brightness.
Fixed, Directional Shading mode: "lightabsolute" / "lightfloorabsolute" properties were checked incorrectly.

Added "Apply Directional Shading" mode. It can be used to apply directional colored flat shading to sloped terrain sectors (line and vertex slopes are supported) and sidedefs.
Updated ZDoom ACC.
Updated ZDoom_ACS.cfg.

Changed, Game configurations: "default" property is no longer mandatory for universal field definitions.
Fixed, Game Configurations window: map resources were not marked for reloading after pasting resources to currently used game configuration.
Fixed, Game configurations: "Platform Generic Change" action's arg2 value must be in octics.

Fixed: copied sidedef settings were not applied when using "Paste properties" and "Paste properties special" actions in Doom/Hexen map formats.

Fixed map lumps duplication when saving the map several times after converting the map from/to UDMF map format by changing it in the Map Options window.
Fixed, cosmetic: in some cases incorrect resource loading time was displayed after saving the map.

Changed, Sector drawing: sector height is set to 0 when the nearest sector's height is < 0 (previously default sector height was used when the nearest sector's height was <= 0).

Removed, GLDEFS parser: removed GLOOME glow definitions support code.

A minor code refactoring.

Updated, Curve Linedefs mode: distance/angle are now changed using bigger increments when being modified by mouse-dragging. You can hold Shift to enable increments by 1 unit.
Updated, Curve Linedefs mode: changing angle by mouse-dragging when "Fixed circular curve" option is enabled is now performed in a more predictable way.
Updated, Curve Linedefs mode: generated geometry is now merged with existing geometry.
Added, Curve Linedefs mode: a hint label is now displayed when modifying settings using mouse-dragging.
Added, Curve Linedefs mode: number of curve vertices can now be changed using LMB+RMB-drag.

Optimized map geometry merging performance when pasting map geometry.
Added, Curve Linedefs mode: added "Flip Curve" button.
Updater: partially rewrote fix from the previous commit.

Changed, Curve Linedefs mode: re-designed the mode UI. Alternative control options are now available (check Help tab while the mode is active).
Changed, Curve Linedefs mode: changed curve generation logic. Setting Distance to 0 will now divide selected linedefs into equal parts.
Changed, Curve Linedefs mode: curve vertices are now drawn.
Updated ZDoom_DECORATE.cfg.

Added, Game configurations: added "ignoreddirectories" parameter. It lists directory names to be ignored when loading PK3/PK7/Directory resources.
Added, Game configurations: added "ignoredextensions" parameter. It lists file extensions to be ignored when loading PK3/PK7/Directory resources.
Updated: sector triangulation logic now works ~20% faster.
Changed: a case when a pk3/pk7 archive contains several entries with identical filename is now treated as a warning, not as an error.
Fixed, Visual mode: absolute floor/ceiling brightness should not be affected by brightness transfer effects (like 3d floors).
Fixed, Draw Lines mode: in some cases unclosed sectors were created when several points were successively drawn at the same location.
Updated documentation. 

Updater: moved SharpCompress code into a separate embedded library. Seems to stop some anti-viruses detecting it as a trojan/virus.
Updated ZDoom_DECORATE.cfg (A_SetInventory).

Updated ZDoom_DECORATE.cfg.
Updated documentation ("Game Configuration - Sectors Settings" page).

Added: some numeric text inputs now support expressions (e.g. (23+15)*1.5). - inspired by https://www.doomworld.com/vb/doom-editing/91089-gzdoombuilder-patch-expression-evaluation-for-sector-heights/
Fixed, Game Configurations window: fixed a crash when switching to a game engine without the file path using the "Engine" drop-down.

Changed the way editor is closed during the update process (updater now asks to close the editor after downloading the update package).
Added write access check before performing the update.
The editor can now update the updater.
Updater: merged relevant parts of SharpCompress into the updater source, reducing updater file size from 900 kb to 150 kb.
Updated ZDoom_DECORATE.cfg.

Updater: error messages now display more info.
Updater: editor closing step is now performed after downloading the update.
Updater: added taskbar progress indication.
NOTICE: to obtain the updated updater, you'll need to download GZDB manually from http://devbuilds.drdteam.org/doombuilder2-gzdb/, because the updater can't update itself.
Added Updater source.

Added, Things mode: sound radii are now shown for "Custom Ambient Sound" and "Custom Ambient Sound (no gravity)" things.

Updated, Visual mode: unflipped FLATSPRITEs.
Updated, DECORATE parser: added duplicate actor definition check.

Fixed, Visual mode: things in sectors affected by line slope effect were not updated when sector height was indirectly changed.
Game configurations: added "internalsoundnames" property.
Updated documentation ("Game Configuration - Basic Settings" page).

Added, Things mode: minimum/maximum sound radii can now be displayed for ZDoom's Ambient Sound things.
Added, Things mode: added "Show Light Radii" and "Show Sound Radii" main toolbar and View menu buttons.
Fixed, Action arguments control: invisible splitter between args1-3 and args4-5 is no longer draggable.
Updated ZDoom ACC (SetTranslation).
Updated ZDoom_ACS.cfg (SetTranslation).