--- a/mercurial/commands.py Thu Dec 10 13:15:15 2020 -0500
+++ b/mercurial/commands.py Thu Dec 10 12:00:45 2020 -0800
@@ -2483,14 +2483,17 @@
default to comparing against the working directory's first
parent changeset if no revisions are specified.
- When two revision arguments are given, then changes are shown
- between those revisions. If only one revision is specified then
- that revision is compared to the working directory, and, when no
- revisions are specified, the working directory files are compared
- to its first parent.
-
- Alternatively you can specify -c/--change with a revision to see
- the changes in that changeset relative to its first parent.
+ By default, the working directory files are compared to its first parent. To
+ see the differences from another revision, use --from. To see the difference
+ to another revision, use --to. For example, :hg:`diff --from .^` will show
+ the differences from the working copy's grandparent to the working copy,
+ :hg:`diff --to .` will show the diff from the working copy to its parent
+ (i.e. the reverse of the default), and :hg:`diff --from 1.0 --to 1.2` will
+ show the diff between those two revisions.
+
+ Alternatively you can specify -c/--change with a revision to see the changes
+ in that changeset relative to its first parent (i.e. :hg:`diff -c 42` is
+ equivalent to :hg:`diff --from 42^ --to 42`)
Without the -a/--text option, diff will avoid generating diffs of
files it detects as binary. With -a, diff will generate a diff