demos: add demo showing how conflicting commits can be rebased etc

README.md

@@ -76,9 +76,14 @@ Features:
    This design also lets Jujutsu rebase merge commits correctly (unlike both Git
    and Mercurial).
 
+   Basic conflict resolution:
    <a href="https://asciinema.org/a/MWQz2nAprRXevQEYtaHScN2tJ" target="_blank">
      <img src="https://asciinema.org/a/MWQz2nAprRXevQEYtaHScN2tJ.svg" />
    </a>
+   Juggling conflicts:
+   <a href="https://asciinema.org/a/HqYA9SL2tzarPAErpYs684GGR" target="_blank">
+     <img src="https://asciinema.org/a/HqYA9SL2tzarPAErpYs684GGR.svg" />
+   </a>
 
  * **Automatic rebase**
 

demos/demo_juggle_conflicts.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+set -euo pipefail
+. "$(dirname "$0")"/demo_helpers.sh
+parse_args "$@"
+
+new_tmp_dir
+jj init
+echo "first" > file
+jj branch first
+jj close -m 'first' 
+echo "second" > file
+jj branch second
+jj close -m 'second' 
+echo "third" > file
+jj branch third
+jj close -m 'third' 
+
+run_demo 'Juggling conflicts' '
+run_command "# We are in a repo with three commits, all"
+run_command "# editing the same line:"
+run_command "jj log"
+pause 3
+
+run_command "jj diff -r first"
+pause 1
+run_command "jj diff -r second"
+pause 1
+run_command "jj diff -r third"
+run_command ""
+pause 2
+
+run_command "# Let'\''s reorder the second and third commits:"
+run_command "jj rebase -s third -d first"
+run_command "jj rebase -s second -d third"
+run_command "jj log"
+pause 3
+run_command "# The commit labeled \"third\" has a conflict,"
+run_command "# as expected. What'\''s more interesting is"
+run_command "# that the top commit has no conflict! That'\''s"
+run_command "# because it has the changes from all three"
+run_command "# commits applied to it."
+run_command ""
+pause 5
+
+run_command "# Let'\''s verify that by looking at its contents:"
+run_command "jj co second"
+run_command "cat file"
+run_command ""
+pause 3
+
+run_command "# Let'\''s now instead make \"second\" and \"third\""
+run_command "# sibling and merge them:"
+run_command "jj rebase -s second -d first"
+run_command "jj merge second third -m merged"
+run_command "jj log"
+pause 3
+run_command "# Again, because the merge commit has the"
+run_command "# changes from all three commits, it has no"
+run_command "# conflict."
+'