This problem was reported in https://github.com/git-for-windows/git/issues/2677, but the problem actually lies with git diff --raw, and it seems that the bug has been with us ever since --intent-to-add was introduced. Changes since v4: * Improved both commit messages after feedback from Junio. Changes since v3: * Instead of showing the same OID in git diff-files --raw as in git diff-files -p for intent-to-add files, we now imitate the logic for modified (non-intent-to-add) files: we show the "null" OID (i.e. all-zero). * As a consequence, we no longer just undo the inadvertent change where intent-to-add files were reported with the empty tree instead of the empty blob, but we fix the bug that has been with us since run_diff_files() was taught about intent-to-add files, i.e. we fix the original bug of 425a28e0a4e (diff-lib: allow ita entries treated as "not yet exist in index", 2016-10-24), at long last. Changes since v2: * Now we also drop the no-longer-used definition of hash_t in t2203. Changes since v1: * Rebased onto sk/diff-files-show-i-t-a-as-new. * Verified that sk/diff-files-show-i-t-a-as-new does not completely resolve the issue (the --raw output still claims the empty blob as the post-image, although the difftool symptom "went away"). * Amended the central patch of this PR to include a fix for the regression test that was introduced in sk/diff-files-show-i-t-a-as-new: it expected the raw diff to contain the hash of the empty tree object (which is incorrect no matter how you turn it: any hash in any raw diff should refer to blob objects). * Reordered the patches so that the central patch comes first (otherwise, the "empty tree" fix would cause a test failure in t2203). Johannes Schindelin (2): diff-files --raw: show correct post-image of intent-to-add files difftool -d: ensure that intent-to-add files are handled correctly diff-lib.c | 3 +-- t/t2203-add-intent.sh | 5 ++--- t/t7800-difftool.sh | 8 ++++++++ 3 files changed, 11 insertions(+), 5 deletions(-) base-commit: feea6946a5b746ff4ebf8ccdf959e303203a6011 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-654%2Fdscho%2Fdifftool-ita-v5 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-654/dscho/difftool-ita-v5 Pull-Request: https://github.com/gitgitgadget/git/pull/654 Range-diff vs v4: 1: 69256ab910 ! 1: 4392ae4be6 diff-files --raw: show correct post-image of intent-to-add files @@ Commit message [...] 0{40} if creation, unmerged or "look at work tree". - This happens for example when showing modified, unstaged files. + on the right hand (i.e. postimage) side. This happens for files that + have unstaged modifications, and for files that are unmodified but + stat-dirty. For intent-to-add files, we used to show the empty blob's hash instead. In c26022ea8f5 (diff: convert diff_addremove to struct object_id, 2017-05-30), we made that worse by inadvertently changing that to the hash of the empty tree. - Let's make the behavior consistent with modified files by showing + Let's make the behavior consistent with files that have unstaged + modifications (which applies to intent-to-add files, too) by showing all-zero values also for intent-to-add files. Accordingly, this patch adjusts the expectations set by the regression 2: 9bb8d84ea9 ! 2: 5f933e852a difftool -d: ensure that intent-to-add files are handled correctly @@ Commit message In https://github.com/git-for-windows/git/issues/2677, a `git difftool -d` problem was reported. The underlying cause was a bug in `git - diff-files --raw` that we just fixed. + diff-files --raw` that we just fixed: it reported intent-to-add files + with the empty _tree_ as the post-image OID, when we need to show + an all-zero (or, "null") OID instead, to indicate to the caller that + they have to look at the worktree file. + + The symptom of that problem shown by `git difftool` was this: + + error: unable to read sha1 file of <path> (<empty-tree-OID>) + error: could not write '<filename>' Make sure that the reported `difftool` problem stays fixed. -- gitgitgadget
