Pass empty attribute value through stack (backport #1719)

[mergify]

This is an automatic backport of pull request #1719 done by Mergify.

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[codecov]

Codecov Report

Merging #1723 (0216b6d) into releases/v0.4x (8f3f0de) will increase coverage by 0.02%.
The diff coverage is n/a.

Additional details and impacted files

@@                Coverage Diff                 @@
##           releases/v0.4x    #1723      +/-   ##
==================================================
+ Coverage           57.58%   57.60%   +0.02%     
==================================================
  Files                  64       64              
  Lines                8770     8770              
==================================================
+ Hits                 5050     5052       +2     
+ Misses               3290     3289       -1     
+ Partials              430      429       -1     

see 1 file with indirect coverage changes