How do I apply a diff patch on Windows?

Question

Apply Patch

With TortoiseMerge:

1. Find and open an existing SVN repo directory
2. Create a new directory named "merges", if it does not exist already
3. Copy the file onto which you want to apply the .patch file
4. ADD and COMMIT to the svn repository before you continue to the next step
5. Right click on merges and choose Apply patch...
6. Double click the file from list
7. The patched file with diff is displayed on the right pane
8. Click on that pane and hit Save or export with File->Save As...

Alternative screeny if you Open from TortoiseMerge. In the screeny below, directory refers to the "merges" directory mentioned at step 2 above:

Screenshot of WinMerge GUI:

I made pure Python tool just for that. It has predictable cross-platform behavior. Although it doesn't create new files (at the time of writing this) and lacks a GUI, it can be used as a library to create graphic tool.

UPDATE: It should be more convenient to use it if you have Python installed.

pip install patch
python -m patch

TortoiseMerge is a separate utility that comes bundled with TortoiseSVN.

It can also be can be downloaded separately in the TortoiseDiff.zip archive. This will allow you to apply unified diffs to non-versioned files.

I know you said you would prefer a GUI, but the commandline tools will do the work nicely. See GnuWin for a port of unix tools to Windows. You'd need the patch command, obviously ;-)

You might run into a problem with the line termination, though. The GnuWin port will assume that the patchfile has DOS style line termination (CR/LF). Try to open the patchfile in a reasonably smart editor and it will convert it for you.

The patch.exe utility from the Git installation works on Windows 10.

Install Git for Windows then use the "C:\Program Files\Git\usr\bin\patch.exe" command to apply a patch.

If any error message like a Hunk #1 FAILED at 1 (different line endings). had been got on the output during applying a patch, try to add the -l (that is a shortcut for the --ignore-whitespace) or the --binary switches to the command line.

In TortoiseSVN, patch applying does work. You need to apply the patch to the same directory as it was created from. It is always important to keep this in mind. So here's how you do it in TortoiseSVN:

Right click on the folder you want to apply the patch to. It will present a dialog asking for the location of the patch file. Select the file and this should open up a little file list window that lists the changed files, and clicking each item should open a diff window that shows what the patch is about to do to that file.

Good luck.