For some reason, projects tracks local copy of released version of other projects, and backports change to earlier version. Due to lower number of object in simplified history, abbreviated object id has fewer characters, thus generate some noise when projects try to compare the backported patch with original patch if the file hunk is an exact match. This series try to lower that noise. Since this is very localised use case, and the noise is not completely eliminated, other experienced developers may have better opinions. Đoàn Trần Công Danh (2): revision: differentiate if --no-abbrev asked explicitly diff: extend --abbrev support to diff-patch format Documentation/diff-options.txt | 9 +++--- diff.c | 5 +++- revision.c | 2 +- t/t4013-diff-various.sh | 3 ++ ...ff.diff-tree_--root_-p_--abbrev=10_initial | 29 +++++++++++++++++++ ...--root_-p_--full-index_--abbrev=10_initial | 29 +++++++++++++++++++ ...f.diff-tree_--root_-p_--full-index_initial | 29 +++++++++++++++++++ 7 files changed, 100 insertions(+), 6 deletions(-) create mode 100644 t/t4013/diff.diff-tree_--root_-p_--abbrev=10_initial create mode 100644 t/t4013/diff.diff-tree_--root_-p_--full-index_--abbrev=10_initial create mode 100644 t/t4013/diff.diff-tree_--root_-p_--full-index_initial -- 2.28.0.215.g32ffa52ee0