Bug 359840

It's not a bug actually, but very strange behavior for advanced text editor.
Accordingly to source code radio button "Increase indentations level if in leading blank space" enables so called "Smart Tab Mode":
KateDocumentConfig::global()->setTabHandling(KateDocumentConfig::tabSmart);

But it works in absolutely opposite way than expected.
When we say about "Smart Tabs" usually is mentioned something like described here: https://www.emacswiki.org/emacs/SmartTabs

Short quote from link above: "There is a semantic way of using tab characters in source code: tabs for indentation, spaces for alignment. This ensures that the code is displayed correctly everywhere, regardless of the viewer’s tab size."

Reproducible: Always

Steps to Reproduce:
1. Start any application based on ktexteditor component (e.g. kate)
2. Go to Indentation Config dialog (Kate-specific example: Settings -> Configure Kate... -> Editing -> Indentation)
3. Select Default indentation mode: Normal
Check radio button "Tabulators and spaces" in "Indent using:" group box.
Check radio button "Increase indentations level if in leading blank space"
4. Press "Tab"
5. Input some keyword
6. Press "Tab" again

Actual Results:  
String "....keyword\t", where
'.' - space symbol,
\t - tabulator;


Expected Results:  
String "\tkeyword...."

ktexteditor version 5.19.0