Re: [PATCH v3 02/13] Documentation/technical: describe remembering renames optimization

On Thu, May 20, 2021 at 4:32 AM Bagas Sanjaya [off-list ref] wrote:

On 20/05/21 13.09, Elijah Newren via GitGitGadget wrote:

quoted

+Outline:
+
+  0. Assumptions
+
+  1. How rebasing and cherry-picking work
+
+  2. Why the renames on MERGE_SIDE1 in any given pick are *always* a
+     superset of the renames on MERGE_SIDE1 for the next pick.
+
+  3. Why any rename on MERGE_SIDE1 in any given pick is _almost_ always also
+     a rename on MERGE_SIDE1 for the next pick
+
+  4. A detailed description of the the counter-examples to #3.
+
+  5. Why the special cases in #4 are still fully reasonable to use to pair
+     up files for three-way content merging in the merge machinery, and why
+     they do not affect the correctness of the merge.
+
+  6. Interaction with skipping of "irrelevant" renames
+
+  7. Additional items that need to be cached
+
+  8. How directory rename detection interacts with the above and why this
+     optimization is still safe even if merge.directoryRenames is set to
+     "true".
+
+

For item 1, 2, 3, 5, 8, it seems that you form question sentences but ended
with dot, instead of question mark (?). Are these question sentences or
descriptive sentences?

I should probably just leave off the ending punctuation on all of
these (looks like I goofed on items 2, 4, 5, and 8), since these are
headings and not full sentences.  For example, item 1 is "Here is a
description of how rebasing and cherry-picking work".  Titles are
often just sentence fragments because they're trying to be concise
while highlighting some kind of summary of what their
section/chapter/part/whatever contains.

quoted

+=== 0. Assumptions ===
+
+There are two assumptions that will hold throughout this document:
+
+  * The upstream side where commits are transplanted to is treated as the
+    first parent side when rebase/cherry-pick call the merge machinery
+
+  * All merges are fully automatic
+

Did you mean that "fully automatic" merges are merges that can be done
without conflicts?

No, as stated below when I explain that assumption, I mean "there is
no interruption for a user to resolve conflicts or to just further
edit or tweak files".  The fact that a merge can be done without
conflicts isn't enough, the user also needs to not interrupt the
process (as in using 'edit' in an interactive rebase) as well.