Topo-sort before --simplify-merges

This makes the algorithm more honest about what it is doing.

We start from an already limited, topo-sorted list, and postprocess
it by simplifying the irrelevant merges away.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/revision.c b/revision.c
index 662d66be7e23792c88907142a48dbc7fbdc7f70e..0aaa4c10b9692b39eb3dfb1cf0e45890d598550e 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -1493,6 +1493,8 @@ static void simplify_merges(struct rev_info *revs)
        struct commit_list *list;
        struct commit_list *yet_to_do, **tail;
 
+       sort_in_topological_order(&revs->commits, revs->lifo);
+
        /* feed the list reversed */
        yet_to_do = NULL;
        for (list = revs->commits; list; list = list->next)
@@ -1522,9 +1524,6 @@ static void simplify_merges(struct rev_info *revs)
                if (commit->util == commit)
                        tail = &commit_list_insert(commit, tail)->next;
        }
-
-       /* sort topologically at the end */
-       sort_in_topological_order(&revs->commits, revs->lifo);
 }
 
 static void set_children(struct rev_info *revs)

diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh
new file mode 100755 (executable)
index 0000000..510bb96
--- /dev/null
+++ b/t/t6012-rev-list-simplify.sh
@@ -0,0 +1,93 @@
+#!/bin/sh
+
+test_description='merge simplification'
+
+. ./test-lib.sh
+
+note () {
+       git tag "$1"
+}
+
+_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+
+unnote () {
+       git name-rev --tags --stdin | sed -e "s|$_x40 (tags/\([^)]*\)) |\1 |g"
+}
+
+test_expect_success setup '
+       echo "Hi there" >file &&
+       git add file &&
+       test_tick && git commit -m "Initial file" &&
+       note A &&
+
+       git branch other-branch &&
+
+       echo "Hello" >file &&
+       git add file &&
+       test_tick && git commit -m "Modified file" &&
+       note B &&
+
+       git checkout other-branch &&
+
+       echo "Hello" >file &&
+       git add file &&
+       test_tick && git commit -m "Modified the file identically" &&
+       note C &&
+
+       echo "This is a stupid example" >another-file &&
+       git add another-file &&
+       test_tick && git commit -m "Add another file" &&
+       note D &&
+
+       test_tick && git merge -m "merge" master &&
+       note E &&
+
+       echo "Yet another" >elif &&
+       git add elif &&
+       test_tick && git commit -m "Irrelevant change" &&
+       note F &&
+
+       git checkout master &&
+       echo "Yet another" >elif &&
+       git add elif &&
+       test_tick && git commit -m "Another irrelevant change" &&
+       note G &&
+
+       test_tick && git merge -m "merge" other-branch &&
+       note H &&
+
+       echo "Final change" >file &&
+       test_tick && git commit -a -m "Final change" &&
+       note I
+'
+
+FMT='tformat:%P        %H | %s'
+
+check_result () {
+       for c in $1
+       do
+               echo "$c"
+       done >expect &&
+       shift &&
+       param="$*" &&
+       test_expect_success "log $param" '
+               git log --pretty="$FMT" --parents $param |
+               unnote >actual &&
+               sed -e "s/^.*   \([^ ]*\) .*/\1/" >check <actual &&
+               test_cmp expect check || {
+                       cat actual
+                       false
+               }
+       '
+}
+
+check_result 'I H G F E D C B A' --full-history
+check_result 'I H E C B A' --full-history -- file
+check_result 'I H E C B A' --full-history --topo-order -- file
+check_result 'I H E C B A' --full-history --date-order -- file
+check_result 'I E C B A' --simplify-merges -- file
+check_result 'I B A' -- file
+check_result 'I B A' --topo-order -- file
+
+test_done