Eric Sunshine <sunshine@xxxxxxxxxxxxxx> writes: > When submitting a revised a patch series, the --range-diff option embeds > a range-diff in the cover letter showing changes since the previous > version of the patch series. The argument to --range-diff is a simple > revision naming the tip of the previous series, which works fine if the > previous and current versions of the patch series share a common base. > > However, it fails if the revision ranges of the old and new versions of > the series are disjoint. To address this shortcoming, extend > --range-diff to also accept an explicit revision range for the previous > series. For example: > > git format-patch --cover-letter --range-diff=v1~3..v1 -3 v2 > > Signed-off-by: Eric Sunshine <sunshine@xxxxxxxxxxxxxx> > --- Makes sense. Even though a single "common rev" would serve as a feature to discourage rebasing done "just to catch up" without a good reason, it is a good idea to give an escape hatch like this to support a case where rebasing is the right thing to do. > static void infer_range_diff_ranges(struct strbuf *r1, > struct strbuf *r2, > const char *prev, > + struct commit *origin, > struct commit *head) > { > const char *head_oid = oid_to_hex(&head->object.oid); > > - strbuf_addf(r1, "%s..%s", head_oid, prev); > - strbuf_addf(r2, "%s..%s", prev, head_oid); I thought "git range-diff" also took the three-dot notation as a short-hand but there is no point using that in this application, which wants the RHS and the LHS range in separate output variables. > + if (!strstr(prev, "..")) { > + strbuf_addf(r1, "%s..%s", head_oid, prev); > + strbuf_addf(r2, "%s..%s", prev, head_oid); > + } else if (!origin) { > + die(_("failed to infer range-diff ranges")); > + } else { > + strbuf_addstr(r1, prev); > + strbuf_addf(r2, "%s..%s", > + oid_to_hex(&origin->object.oid), head_oid); Interesting. I actually would feel better to see the second range for the normal case to be computed exactly the same way, i.e. int prev_is_range = strstr(prev, ".."); if (prev_is_range) strbuf_addstr(r1, prev); else strbuf_addf(r1, "%s..%s", head_oid, prev); if (origin) strbuf_addf(r2, "%s..%s", oid_to_hex(&origin->object.oid, head_oid); else if (prev_is_range) die("cannot figure out the origin of new series"); else { warning("falling back to use '%s' as the origin of new series", prev); strbuf_addf(r2, "%s..%s", prev, head_oid); } because origin..HEAD is always the set of the "new" series, no matter what "prev" the user chooses to compare that series against, when there is a single "origin".