merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 204 insertions, 0 deletions

diff --git a/third_party/git/t/t6418-merge-text-auto.sh b/third_party/git/t/t6418-merge-text-auto.sh
new file mode 100755
index 000000000000..30983d18b1ba
--- /dev/null
+++ b/third_party/git/t/t6418-merge-text-auto.sh
@@ -0,0 +1,204 @@
+#!/bin/sh
+
+test_description='CRLF merge conflict across text=auto change
+
+* [master] remove .gitattributes
+ ! [side] add line from b
+--
+ + [side] add line from b
+*  [master] remove .gitattributes
+*  [master^] add line from a
+*  [master~2] normalize file
+*+ [side^] Initial
+'
+
+. ./test-lib.sh
+
+test_have_prereq SED_STRIPS_CR && SED_OPTIONS=-b
+
+compare_files () {
+	tr '\015\000' QN <"$1" >"$1".expect &&
+	tr '\015\000' QN <"$2" >"$2".actual &&
+	test_cmp "$1".expect "$2".actual &&
+	rm "$1".expect "$2".actual
+}
+
+test_expect_success setup '
+	git config core.autocrlf false &&
+
+	echo first line | append_cr >file &&
+	echo first line >control_file &&
+	echo only line >inert_file &&
+
+	git add file control_file inert_file &&
+	test_tick &&
+	git commit -m "Initial" &&
+	git tag initial &&
+	git branch side &&
+
+	echo "* text=auto" >.gitattributes &&
+	echo first line >file &&
+	git add .gitattributes file &&
+	test_tick &&
+	git commit -m "normalize file" &&
+
+	echo same line | append_cr >>file &&
+	echo same line >>control_file &&
+	git add file control_file &&
+	test_tick &&
+	git commit -m "add line from a" &&
+	git tag a &&
+
+	git rm .gitattributes &&
+	rm file &&
+	git checkout file &&
+	test_tick &&
+	git commit -m "remove .gitattributes" &&
+	git tag c &&
+
+	git checkout side &&
+	echo same line | append_cr >>file &&
+	echo same line >>control_file &&
+	git add file control_file &&
+	test_tick &&
+	git commit -m "add line from b" &&
+	git tag b &&
+
+	git checkout master
+'
+
+test_expect_success 'set up fuzz_conflict() helper' '
+	fuzz_conflict() {
+		sed $SED_OPTIONS -e "s/^\([<>=]......\) .*/\1/" "$@"
+	}
+'
+
+test_expect_success 'Merge after setting text=auto' '
+	cat <<-\EOF >expected &&
+	first line
+	same line
+	EOF
+
+	if test_have_prereq NATIVE_CRLF; then
+		append_cr <expected >expected.temp &&
+		mv expected.temp expected
+	fi &&
+	git config merge.renormalize true &&
+	git rm -fr . &&
+	rm -f .gitattributes &&
+	git reset --hard a &&
+	git merge b &&
+	compare_files expected file
+'
+
+test_expect_success 'Merge addition of text=auto eol=LF' '
+	git config core.eol lf &&
+	cat <<-\EOF >expected &&
+	first line
+	same line
+	EOF
+
+	git config merge.renormalize true &&
+	git rm -fr . &&
+	rm -f .gitattributes &&
+	git reset --hard b &&
+	git merge a &&
+	compare_files  expected file
+'
+
+test_expect_success 'Merge addition of text=auto eol=CRLF' '
+	git config core.eol crlf &&
+	cat <<-\EOF >expected &&
+	first line
+	same line
+	EOF
+
+	append_cr <expected >expected.temp &&
+	mv expected.temp expected &&
+	git config merge.renormalize true &&
+	git rm -fr . &&
+	rm -f .gitattributes &&
+	git reset --hard b &&
+	echo >&2 "After git reset --hard b" &&
+	git ls-files -s --eol >&2 &&
+	git merge a &&
+	compare_files  expected file
+'
+
+test_expect_success 'Detect CRLF/LF conflict after setting text=auto' '
+	git config core.eol native &&
+	echo "<<<<<<<" >expected &&
+	echo first line >>expected &&
+	echo same line >>expected &&
+	echo ======= >>expected &&
+	echo first line | append_cr >>expected &&
+	echo same line | append_cr >>expected &&
+	echo ">>>>>>>" >>expected &&
+	git config merge.renormalize false &&
+	rm -f .gitattributes &&
+	git reset --hard a &&
+	test_must_fail git merge b &&
+	fuzz_conflict file >file.fuzzy &&
+	compare_files expected file.fuzzy
+'
+
+test_expect_success 'Detect LF/CRLF conflict from addition of text=auto' '
+	echo "<<<<<<<" >expected &&
+	echo first line | append_cr >>expected &&
+	echo same line | append_cr >>expected &&
+	echo ======= >>expected &&
+	echo first line >>expected &&
+	echo same line >>expected &&
+	echo ">>>>>>>" >>expected &&
+	git config merge.renormalize false &&
+	rm -f .gitattributes &&
+	git reset --hard b &&
+	test_must_fail git merge a &&
+	fuzz_conflict file >file.fuzzy &&
+	compare_files expected file.fuzzy
+'
+
+test_expect_success 'checkout -m after setting text=auto' '
+	cat <<-\EOF >expected &&
+	first line
+	same line
+	EOF
+
+	git config merge.renormalize true &&
+	git rm -fr . &&
+	rm -f .gitattributes &&
+	git reset --hard initial &&
+	git restore --source=a -- . &&
+	git checkout -m b &&
+	git diff --no-index --ignore-cr-at-eol expected file
+'
+
+test_expect_success 'checkout -m addition of text=auto' '
+	cat <<-\EOF >expected &&
+	first line
+	same line
+	EOF
+
+	git config merge.renormalize true &&
+	git rm -fr . &&
+	rm -f .gitattributes file &&
+	git reset --hard initial &&
+	git restore --source=b -- . &&
+	git checkout -m a &&
+	git diff --no-index --ignore-cr-at-eol expected file
+'
+
+test_expect_success 'Test delete/normalize conflict' '
+	git checkout -f side &&
+	git rm -fr . &&
+	rm -f .gitattributes &&
+	git reset --hard initial &&
+	git rm file &&
+	git commit -m "remove file" &&
+	git checkout master &&
+	git reset --hard a^ &&
+	git merge side &&
+	test_path_is_missing file
+'
+
+test_done