diff and three way merge tools for encrypted files

[clach04]

For encrypted files need a way to allow diff of 3 / two files and also three-way merge without temporary, unencrypted plain text on disk.

✔️ See ptdiff3merge https://github.com/clach04/puren_tonbo/blob/main/puren_tonbo/tools/ptdiff3merge.py

DMP library is fast and works well (used for PyTombo?) diff_match_patch / diff-match-patch https://github.com/clach04/diff-match-patch (http://code.google.com/p/google-diff-match-patch/)

useful resources

• https://github.com/breezy-team/smartmerge - sample git config and tool for custom merge
• https://www.eseth.org/2020/mergetools.html
• https://github.com/whiteinge/diffconflicts also had sample git config (via command line, rather than config file editing)
  • https://github.com/whiteinge/diffconflicts/tree/master/_utils#readme

test data

• comment missing 3-way merge jelmer/dulwich#754 (comment)
• https://github.com/whiteinge/diffconflicts/tree/master/_utils
• https://github.com/yebrahim/pydiff/tree/master/tests - 2-way diff only

3 way merge libs

• fovi-llc/refactor-python@071abfd
  • Assertion Error and endless loop conditions spyder-ide/three-merge#10
• https://github.com/spyder-ide/three-merge - note the bug (and fix) above
• https://github.com/google/diff-match-patch
• https://github.com/breezy-team/merge3 - py3 only?
• https://gist.github.com/stepchowfun/4713315 py2 only? And only word based (not line based according to comment missing 3-way merge jelmer/dulwich#754 (comment))
• diff3merge.py available anywhere by kevinhendricks?

2 way diff only

• https://github.com/breezy-team/patiencediff
• https://github.com/yebrahim/pydiff to GUI, for files and directories
  • from quick test under Linux, works with both Python 2.7.17 and 3.6.9 (at least for test, 7-bit us-ascii files, [email protected]:clach04/pydiff.git)
  • fork yebrahim/pydiff@master...KyferEz:pydiff:py3compatible has some Python 3 and 2 support (Windows may need this)
  • fork yebrahim/pydiff@master...arturaugusto:pydiff:master uses strings (not bytes), potentially issue for "binary" diff (e.g. different, unknown character sets)
• https://github.com/MightyCreak/diffuse gui, GTK only? Note merge support? Move to three way merge list?

ideas

1. Tool to create final file with auto-resolved merges and also conflict markers for unmergable sections.
2. Web merge tool
3. Plugins to existing tools? https://github.com/WinMerge/winmerge/blob/master/Plugins/README.md supports plugins (I don't think tortoise merge does)
   • WinMerge ExecFilterCommand with pt command line tools (ptcat / ptcipher) potentially could work out of the box (ideally setting password once, assuming all 3 files have same password to avoid 3 password prompts for 3-way-merge and 2 for diff)
4. Git sample config for using an encrypted merge tool