SUMMARY
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Dolphin does not find any Hidden Files even when "Show Hidden Files" is on.
No results for filename search, nor for content search.
=> There is no way to use search in Dolphin reliably.
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STEPS TO REPRODUCE
1. Open Dolphin in the home directory. The directory has hidden file, e.g. ".bashrc".
2. Check that "Show Hidden Files" option is set on and ".bashrc" is visible in the directory.
3. Try to search for "bash" using Search panel in Dolphin.

OBSERVED RESULT
No ".bashrc" found in the results, Dolphin states there is no such file after showing it before search.

EXPECTED RESULT
The ".bashrc" file found and is shown in the search results.

ADDITIONAL INFORMATION
The issue affects Content search too. One can search for something but hidden files will be skipped and the search result will be wrong (without actual expected file).

SUMMARY
Please make search not to ignore hidden files. Because: 
1) Other software does not behave like that and provide reliable search results (e.g. mc)
2) It's completely unexpected by the user who has Show Hidden Files ALWAYS ON and does not care if the file starts with dot at all.
3) The current search method is not reliable. Dolphin states there is not file with the provided name but actually there is one. Dolphin states there is no file with provided content and it's false also.