On Windows, it is not possible to overwrite a file as long as any process holds a read handle to it. Even keeping regions memory-mapped prevents that. When git difftool calls git diff, it might be the user's intention to write the file(s) via the diff tool, so let's make sure that they are not memory-mapped at that stage. Johannes Schindelin (1): diff: munmap() file contents before running external diff diff.c | 4 ++++ 1 file changed, 4 insertions(+) base-commit: aa25c82427ae70aebf3b8f970f2afd54e9a2a8c6 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-213%2Fdscho%2Fmunmap-before-ext-diff-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-213/dscho/munmap-before-ext-diff-v1 Pull-Request: https://github.com/gitgitgadget/git/pull/213 -- gitgitgadget