t6012: make rev-list tests more interesting

As we are working to rewrite some of the revision-walk machinery,
there could easily be some interesting interactions between the
options that force topological constraints (--topo-order,
--date-order, and --author-date-order) along with specifying a
path.

Add extra tests to t6012-rev-list-simplify.sh to add coverage of
these interactions. To ensure interesting things occur, alter the
repo data shape to have different orders depending on topo-, date-,
or author-date-order.

When testing using GIT_TEST_COMMIT_GRAPH, this assists in covering
the new logic for topo-order walks using generation numbers. The
extra tests can be added indepently.

Signed-off-by: Derrick Stolee <[email protected]>

Author: derrickstolee

t/t6012-rev-list-simplify.sh

@@ -12,6 +12,22 @@ unnote () {
 	git name-rev --tags --stdin | sed -e "s|$OID_REGEX (tags/\([^)]*\)) |\1 |g"
 }
 
+#
+# Create a test repo with interesting commit graph:
+#
+# A--B----------G--H--I--K--L
+#  \  \           /     /
+#   \  \         /     /
+#    C------E---F     J
+#        \_/
+#
+# The commits are laid out from left-to-right starting with
+# the root commit A and terminating at the tip commit L.
+#
+# There are a few places where we adjust the commit date or
+# author date to make the --topo-order, --date-order, and
+# --author-date-order flags produce different output.
+
 test_expect_success setup '
 	echo "Hi there" >file &&
 	echo "initial" >lost &&
@@ -21,10 +37,18 @@ test_expect_success setup '
 
 	git branch other-branch &&
 
+	git symbolic-ref HEAD refs/heads/unrelated &&
+	git rm -f "*" &&
+	echo "Unrelated branch" >side &&
+	git add side &&
+	test_tick && git commit -m "Side root" &&
+	note J &&
+	git checkout master &&
+
 	echo "Hello" >file &&
 	echo "second" >lost &&
 	git add file lost &&
-	test_tick && git commit -m "Modified file and lost" &&
+	test_tick && GIT_AUTHOR_DATE=$(($test_tick + 120)) git commit -m "Modified file and lost" &&
 	note B &&
 
 	git checkout other-branch &&
@@ -63,13 +87,6 @@ test_expect_success setup '
 	test_tick && git commit -a -m "Final change" &&
 	note I &&
 
-	git symbolic-ref HEAD refs/heads/unrelated &&
-	git rm -f "*" &&
-	echo "Unrelated branch" >side &&
-	git add side &&
-	test_tick && git commit -m "Side root" &&
-	note J &&
-
 	git checkout master &&
 	test_tick && git merge --allow-unrelated-histories -m "Coolest" unrelated &&
 	note K &&
@@ -103,14 +120,24 @@ check_result () {
 	check_outcome success "$@"
 }
 
-check_result 'L K J I H G F E D C B A' --full-history
+check_result 'L K J I H F E D C G B A' --full-history --topo-order
+check_result 'L K I H G F E D C B J A' --full-history
+check_result 'L K I H G F E D C B J A' --full-history --date-order
+check_result 'L K I H G F E D B C J A' --full-history --author-date-order
 check_result 'K I H E C B A' --full-history -- file
 check_result 'K I H E C B A' --full-history --topo-order -- file
 check_result 'K I H E C B A' --full-history --date-order -- file
+check_result 'K I H E B C A' --full-history --author-date-order -- file
 check_result 'I E C B A' --simplify-merges -- file
+check_result 'I E C B A' --simplify-merges --topo-order -- file
+check_result 'I E C B A' --simplify-merges --date-order -- file
+check_result 'I E B C A' --simplify-merges --author-date-order -- file
 check_result 'I B A' -- file
 check_result 'I B A' --topo-order -- file
+check_result 'I B A' --date-order -- file
+check_result 'I B A' --author-date-order -- file
 check_result 'H' --first-parent -- another-file
+check_result 'H' --first-parent --topo-order -- another-file
 
 check_result 'E C B A' --full-history E -- lost
 test_expect_success 'full history simplification without parent' '