log: add log.excludeDecoration config option

In 'git log', the --decorate-refs-exclude option appends a pattern
to a string_list. This list is used to prevent showing some refs
in the decoration output, or even by --simplify-by-decoration.

Users may want to use their refs space to store utility refs that
should not appear in the decoration output. For example, Scalar [1]
runs a background fetch but places the "new" refs inside the
refs/scalar/hidden/<remote>/* refspace instead of refs/<remote>/*
to avoid updating remote refs when the user is not looking. However,
these "hidden" refs appear during regular 'git log' queries.

A similar idea to use "hidden" refs is under consideration for core
Git [2].

Add the 'log.excludeDecoration' config option so users can exclude
some refs from decorations by default instead of needing to use
--decorate-refs-exclude manually. The config value is multi-valued
much like the command-line option. The documentation is careful to
point out that the config value can be overridden by the
--decorate-refs option, even though --decorate-refs-exclude would
always "win" over --decorate-refs.

Since the 'log.excludeDecoration' takes lower precedence to
--decorate-refs, and --decorate-refs-exclude takes higher
precedence, the struct decoration_filter needed another field.
This led also to new logic in load_ref_decorations() and
ref_filter_match().

There are several tests in t4202-log.sh that test the
--decorate-refs-(include|exclude) options, so these are extended.
Since the expected output is already stored as a file, most tests
could simply replace a "--decorate-refs-exclude" option with an
in-line config setting. Other tests involve the precedence of
the config option compared to command-line options and needed more
modification.

[1] https://github.com/microsoft/scalar
[2] https://lore.kernel.org/git/77b1da5d3063a2404cd750adfe3bb8be9b6c497d.1585946894.git.gitgitgadget@gmail.com/

Helped-by: Junio C Hamano <gister@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 50 insertions, 1 deletions

diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 5eeb739f3e..f1ea7d97f5 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -742,7 +742,23 @@ test_expect_success 'decorate-refs with glob' '
 	octopus-a (octopus-a)
 	reach
 	EOF
+	cat >expect.no-decorate <<-\EOF &&
+	Merge-tag-reach
+	Merge-tags-octopus-a-and-octopus-b
+	seventh
+	octopus-b
+	octopus-a
+	reach
+	EOF
+	git log -n6 --decorate=short --pretty="tformat:%f%d" \
+		--decorate-refs="heads/octopus*" >actual &&
+	test_cmp expect.decorate actual &&
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
+		--decorate-refs-exclude="heads/octopus*" \
+		--decorate-refs="heads/octopus*" >actual &&
+	test_cmp expect.no-decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs="heads/octopus*" >actual &&
 	test_cmp expect.decorate actual
 '
@@ -787,6 +803,9 @@ test_expect_success 'decorate-refs-exclude with glob' '
 	EOF
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="heads/octopus*" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -801,6 +820,9 @@ test_expect_success 'decorate-refs-exclude without globs' '
 	EOF
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="tags/reach" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="tags/reach" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -816,11 +838,19 @@ test_expect_success 'multiple decorate-refs-exclude' '
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="heads/octopus*" \
 		--decorate-refs-exclude="tags/reach" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" \
+		-c log.excludeDecoration="tags/reach" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="heads/octopus*" log \
+		--decorate-refs-exclude="tags/reach" \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
 test_expect_success 'decorate-refs and decorate-refs-exclude' '
-	cat >expect.decorate <<-\EOF &&
+	cat >expect.no-decorate <<-\EOF &&
 	Merge-tag-reach (master)
 	Merge-tags-octopus-a-and-octopus-b
 	seventh
@@ -831,6 +861,21 @@ test_expect_success 'decorate-refs and decorate-refs-exclude' '
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs="heads/*" \
 		--decorate-refs-exclude="heads/oc*" >actual &&
+	test_cmp expect.no-decorate actual
+'
+
+test_expect_success 'deocrate-refs and log.excludeDecoration' '
+	cat >expect.decorate <<-\EOF &&
+	Merge-tag-reach (master)
+	Merge-tags-octopus-a-and-octopus-b
+	seventh
+	octopus-b (octopus-b)
+	octopus-a (octopus-a)
+	reach (reach)
+	EOF
+	git -c log.excludeDecoration="heads/oc*" log \
+		--decorate-refs="heads/*" \
+		-n6 --decorate=short --pretty="tformat:%f%d" >actual &&
 	test_cmp expect.decorate actual
 '
 
@@ -846,6 +891,10 @@ test_expect_success 'decorate-refs-exclude and simplify-by-decoration' '
 	git log -n6 --decorate=short --pretty="tformat:%f%d" \
 		--decorate-refs-exclude="*octopus*" \
 		--simplify-by-decoration >actual &&
+	test_cmp expect.decorate actual &&
+	git -c log.excludeDecoration="*octopus*" log \
+		-n6 --decorate=short --pretty="tformat:%f%d" \
+		--simplify-by-decoration >actual &&
 	test_cmp expect.decorate actual
 '