Lightroom: Merging DNG images into HDR causes high memory consumption and crash

Hi,

I noticed memory leaks during in HDR merging. Memory consumption goes so high that app stops responding and has to be killed. Issue is 100% reproducible.

Steps to reproduce:
1. Get 4 set of images for HDR merging (each set containing 3 DNG images, 6000 × 4000 pix, ~30MB)
2. Perform first HDR merge, observe RAM consumption
3. Perform next merge

App stops during third merge on my MacBook Air. I would expect memory to go down after processing the first set.

I can provide the DNG files if needed.



System info...
Lightroom version: 2.4 MAS [ 20190802-0905-45e6444 ] (Aug  2 2019)NGL Version: 1.10.0.4
Operating system: macOS
OS Version: 10.14 [6]
Application architecture: x64
Computer model: MacBookAir8,2 / Intel(R) Core(TM) i5-8210Y CPU @ 1.60GHz
Logical processor count: 4
Processor speed: 1,6 GHz
Built-in memory: 8 192,0 MB
Real memory available to Lightroom: 8 192,0 MB
Real memory used by Lightroom: 226,2 MB (2,7%)
Virtual memory used by Lightroom: 5 444,3 MB
Memory cache size: 580,1 MB
Internal Camera Raw version: 11.4 [ 274 ]
Maximum thread count used by Camera Raw: 3
Camera Raw SIMD optimization: SSE2,AVX,AVX2
Camera Raw virtual memory: 3655MB / 4095MB (89%)
Camera Raw real memory: 3652MB / 8192MB (44%)
Displays: 1) 2880x1800

Graphics Processor Info: Metal: Intel(R) UHD Graphics 617

Application folder: /Applications
Settings Folder: /Users/wojtek/Library/Containers/com.adobe.mas.lightroomCC/Data/Library/Application Support/Adobe/Lightroom CC