which was commit 8993f42562696079866fc2dec7191877b6cc1f18 This commit introduced a regression where hunk headers would contain lines taken from below or within a change. Reported by tb@ and sthen@. There is some confusion around how the -p feature was documented: -p With unified and context diffs, show with each change the first 40 characters of the last line before the context beginning with a letter, an underscore or a dollar sign. For C source code following standard layout conventions, this will show the prototype of the function the change applies to. The original behaviour matches "the last line before the context beginning with a letter ...". The new (reverted) behaviour sometimes matches "will show the prototype of the function the change applies to". This did always happen as intended, as seen when some .c files in the OpenBSD src tree were changed. The new behaviour was also worse for Makefiles in the OpenBSD ports tree. Let's revert to the traditional -p behaviour until a better fix is found. Details: https://marc.gameoftrees.org/mail/1692696001.69872_0.html https://marc.info/?l=gameoftrees&m=169269624516330&w=2 ok tb@

As discussed with stsp, reword an easily misunderstood comment, and move diff_chunk_type() into the public diff API to improve caller efficiency. ok stsp@

ok op@

Initial diff by Tom Jones with fixes from stsp. ok stsp@

with + ok naddy

They will be needed to implement 'got stage -p' and 'got revert -p', etc. Chunks stored in diff_result still need post-processing in order to be displayed as expected by diff_output_unidiff_chunk(). Exposing these functions allows API consumers to implement the same chunk merging loop as used internally by output_unidiff() and output_edscript(). (Perhaps, ideally, the public diff API would provide pre-merged chunks at some point in the future? Then this commit could probably be reverted.) Change return values from bool to int to avoid making stdbool.h a requirement for the public diff API.

Not adding new tests since this behaviour is covered by tests in Got.

Now allocating patience specific data only when patience is going to be used. This may allow using forward-Myers more often, since the state size per line is significantly smaller. Patience instead allocates an array, puts it in the current diff_data, and also place a pointer of the current diff_data in the root diff_data (since each atom points to the root diff_data).

The idea was that for each diff box within the files, the atoms would have a backpointer to the current layer of diff_data (indicating the current section), but it is not actually needed to update the backpointer in each atom to the current diff_data. That is why the current code always points atom->d to the root diff_data for the entire file. Clarify by proper name. Constructs like atom->d->root->foo are redundant, just use atom->root->foo.