Merge branch 'ep/shell-assign-and-export-vars' into maint

* ep/shell-assign-and-export-vars:
  scripts: more "export VAR=VALUE" fixes
  scripts: "export VAR=VALUE" construct is not portable

contrib/subtree/t/t7900-subtree.sh

@@ -8,7 +8,8 @@ This test verifies the basic operation of the merge, pull, add
 and split subcommands of git subtree.
 '
 
-export TEST_DIRECTORY=$(pwd)/../../../t
+TEST_DIRECTORY=$(pwd)/../../../t
+export TEST_DIRECTORY
 
 . ../../../t/test-lib.sh
 

git-remote-testgit.sh

@@ -13,7 +13,8 @@ refspec="${GIT_REMOTE_TESTGIT_REFSPEC-$default_refspec}"
 
 test -z "$refspec" && prefix="refs"
 
-export GIT_DIR="$url/.git"
+GIT_DIR="$url/.git"
+export GIT_DIR
 
 force=
 

git-stash.sh

@@ -94,7 +94,8 @@ create_stash () {
 		# ease of unpacking later.
 		u_commit=$(
 			untracked_files | (
-				export GIT_INDEX_FILE="$TMPindex"
+				GIT_INDEX_FILE="$TMPindex" &&
+				export GIT_INDEX_FILE &&
 				rm -f "$TMPindex" &&
 				git update-index -z --add --remove --stdin &&
 				u_tree=$(git write-tree) &&

t/t3032-merge-recursive-options.sh

@@ -14,7 +14,11 @@ test_description='merge-recursive options
 . ./test-lib.sh
 
 test_have_prereq SED_STRIPS_CR && SED_OPTIONS=-b
-test_have_prereq GREP_STRIPS_CR && export GREP_OPTIONS=-U
+if test_have_prereq GREP_STRIPS_CR
+then
+	GREP_OPTIONS=-U
+	export GREP_OPTIONS
+fi
 
 test_expect_success 'setup' '
 	conflict_hunks () {

t/t5560-http-backend-noserver.sh

@@ -5,7 +5,11 @@ test_description='test git-http-backend-noserver'
 
 HTTPD_DOCUMENT_ROOT_PATH="$TRASH_DIRECTORY"
 
-test_have_prereq GREP_STRIPS_CR && export GREP_OPTIONS=-U
+if test_have_prereq GREP_STRIPS_CR
+then
+	GREP_OPTIONS=-U
+	export GREP_OPTIONS
+fi
 
 run_backend() {
 	echo "$2" |