Support showing notes from more than one notes tree

With this patch, you can set notes.displayRef to a glob that points at
your favourite notes refs, e.g.,

[notes]
	displayRef = refs/notes/*

Then git-log and friends will show notes from all trees.

Thanks to Junio C Hamano for lots of feedback, which greatly
influenced the design of the entire series and this commit in
particular.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Acked-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 141 insertions, 8 deletions

diff --git a/t/t3301-notes.sh b/t/t3301-notes.sh
index 90178f96d..cb7166f6e 100755
--- a/t/t3301-notes.sh
+++ b/t/t3301-notes.sh
@@ -415,7 +415,7 @@ Date:   Thu Apr 7 15:18:13 2005 -0700
 
     6th
 
-Notes:
+Notes (other):
     other note
 EOF
 
@@ -448,7 +448,139 @@ test_expect_success 'Do not show note when core.notesRef is overridden' '
 	test_cmp expect-not-other output
 '
 
+cat > expect-both << EOF
+commit 387a89921c73d7ed72cd94d179c1c7048ca47756
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:18:13 2005 -0700
+
+    6th
+
+Notes:
+    order test
+
+Notes (other):
+    other note
+
+commit bd1753200303d0a0344be813e504253b3d98e74d
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:17:13 2005 -0700
+
+    5th
+
+Notes:
+    replacement for deleted note
+EOF
+
+test_expect_success 'Show all notes when notes.displayRef=refs/notes/*' '
+	GIT_NOTES_REF=refs/notes/commits git notes add \
+		-m"replacement for deleted note" HEAD^ &&
+	GIT_NOTES_REF=refs/notes/commits git notes add -m"order test" &&
+	git config --unset core.notesRef &&
+	git config notes.displayRef "refs/notes/*" &&
+	git log -2 > output &&
+	test_cmp expect-both output
+'
+
+test_expect_success 'core.notesRef is implicitly in notes.displayRef' '
+	git config core.notesRef refs/notes/commits &&
+	git config notes.displayRef refs/notes/other &&
+	git log -2 > output &&
+	test_cmp expect-both output
+'
+
+test_expect_success 'notes.displayRef can be given more than once' '
+	git config --unset core.notesRef &&
+	git config notes.displayRef refs/notes/commits &&
+	git config --add notes.displayRef refs/notes/other &&
+	git log -2 > output &&
+	test_cmp expect-both output
+'
+
+cat > expect-both-reversed << EOF
+commit 387a89921c73d7ed72cd94d179c1c7048ca47756
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:18:13 2005 -0700
+
+    6th
+
+Notes (other):
+    other note
+
+Notes:
+    order test
+EOF
+
+test_expect_success 'notes.displayRef respects order' '
+	git config core.notesRef refs/notes/other &&
+	git config --unset-all notes.displayRef &&
+	git config notes.displayRef refs/notes/commits &&
+	git log -1 > output &&
+	test_cmp expect-both-reversed output
+'
+
+test_expect_success 'GIT_NOTES_DISPLAY_REF works' '
+	git config --unset-all core.notesRef &&
+	git config --unset-all notes.displayRef &&
+	GIT_NOTES_DISPLAY_REF=refs/notes/commits:refs/notes/other \
+		git log -2 > output &&
+	test_cmp expect-both output
+'
+
+cat > expect-none << EOF
+commit 387a89921c73d7ed72cd94d179c1c7048ca47756
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:18:13 2005 -0700
+
+    6th
+
+commit bd1753200303d0a0344be813e504253b3d98e74d
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:17:13 2005 -0700
+
+    5th
+EOF
+
+test_expect_success 'GIT_NOTES_DISPLAY_REF overrides config' '
+	git config notes.displayRef "refs/notes/*" &&
+	GIT_NOTES_REF= GIT_NOTES_DISPLAY_REF= git log -2 > output &&
+	test_cmp expect-none output
+'
+
+test_expect_success '--show-notes=* adds to GIT_NOTES_DISPLAY_REF' '
+	GIT_NOTES_REF= GIT_NOTES_DISPLAY_REF= git log --show-notes=* -2 > output &&
+	test_cmp expect-both output
+'
+
+cat > expect-commits << EOF
+commit 387a89921c73d7ed72cd94d179c1c7048ca47756
+Author: A U Thor <author@example.com>
+Date:   Thu Apr 7 15:18:13 2005 -0700
+
+    6th
+
+Notes:
+    order test
+EOF
+
+test_expect_success '--no-standard-notes' '
+	git log --no-standard-notes --show-notes=commits -1 > output &&
+	test_cmp expect-commits output
+'
+
+test_expect_success '--standard-notes' '
+	git log --no-standard-notes --show-notes=commits \
+		--standard-notes -2 > output &&
+	test_cmp expect-both output
+'
+
+test_expect_success '--show-notes=ref accumulates' '
+	git log --show-notes=other --show-notes=commits \
+		 --no-standard-notes -1 > output &&
+	test_cmp expect-both-reversed output
+'
+
 test_expect_success 'Allow notes on non-commits (trees, blobs, tags)' '
+	git config core.notesRef refs/notes/other &&
 	echo "Note on a tree" > expect
 	git notes add -m "Note on a tree" HEAD: &&
 	git notes show HEAD: > actual &&
@@ -472,7 +604,7 @@ Date:   Thu Apr 7 15:19:13 2005 -0700
 
     7th
 
-Notes:
+Notes (other):
     other note
 EOF
 
@@ -503,7 +635,7 @@ Date:   Thu Apr 7 15:21:13 2005 -0700
 
     9th
 
-Notes:
+Notes (other):
     yet another note
 EOF
 
@@ -533,7 +665,7 @@ Date:   Thu Apr 7 15:21:13 2005 -0700
 
     9th
 
-Notes:
+Notes (other):
     yet another note
 $whitespace
     yet another note
@@ -552,7 +684,7 @@ Date:   Thu Apr 7 15:22:13 2005 -0700
 
     10th
 
-Notes:
+Notes (other):
     other note
 EOF
 
@@ -569,7 +701,7 @@ Date:   Thu Apr 7 15:22:13 2005 -0700
 
     10th
 
-Notes:
+Notes (other):
     other note
 $whitespace
     yet another note
@@ -588,7 +720,7 @@ Date:   Thu Apr 7 15:23:13 2005 -0700
 
     11th
 
-Notes:
+Notes (other):
     other note
 $whitespace
     yet another note
@@ -619,7 +751,7 @@ Date:   Thu Apr 7 15:23:13 2005 -0700
 
     11th
 
-Notes:
+Notes (other):
     yet another note
 $whitespace
     yet another note
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 49f06d2b8..90115863b 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -55,6 +55,7 @@ unset GIT_CEILING_DIRECTORIES
 unset SHA1_FILE_DIRECTORIES
 unset SHA1_FILE_DIRECTORY
 unset GIT_NOTES_REF
+unset GIT_NOTES_DISPLAY_REF
 GIT_MERGE_VERBOSITY=5
 export GIT_MERGE_VERBOSITY
 export GIT_AUTHOR_EMAIL GIT_AUTHOR_NAME