for-each-repo: work correctly in a worktree

When run in a worktree, the GIT_DIR directory is set in a different way
than in a typical repository. Show this by updating t0068 to include a
worktree and add a test that runs from that worktree. This requires
moving the repo.key config into a global config instead of the base test
repository's local config (demonstrating that it worked with
non-worktree Git repositories).

The fix is simple: unset the environment variable before looping over
the repos.

Reported-by: Matthew Gabeler-Lee <fastcat@gmail.com>
Signed-off-by: Derrick Stolee <stolee@gmail.com>

Author: derrickstolee

builtin/for-each-repo.c

@@ -1,5 +1,6 @@
 #include "builtin.h"
 #include "config.h"
+#include "environment.h"
 #include "gettext.h"
 #include "parse-options.h"
 #include "path.h"
@@ -60,6 +61,9 @@ int cmd_for_each_repo(int argc,
 	else if (err)
 		return 0;
 
+	/* Be sure to not pass GIT_DIR to children. */
+	unsetenv(GIT_DIR_ENVIRONMENT);
+
 	for (size_t i = 0; i < values->nr; i++) {
 		int ret = run_command_on_repo(values->items[i].string, argc, argv);
 		if (ret) {

t/t0068-for-each-repo.sh

@@ -7,12 +7,13 @@ test_description='git for-each-repo builtin'
 test_expect_success 'run based on configured value' '
 	git init one &&
 	git init two &&
-	git init three &&
+	git -C two worktree add --orphan ../three &&
 	git init ~/four &&
 	git -C two commit --allow-empty -m "DID NOT RUN" &&
-	git config run.key "$TRASH_DIRECTORY/one" &&
-	git config --add run.key "$TRASH_DIRECTORY/three" &&
-	git config --add run.key "~/four" &&
+	git config --global run.key "$TRASH_DIRECTORY/one" &&
+	git config --global --add run.key "$TRASH_DIRECTORY/three" &&
+	git config --global --add run.key "~/four" &&
+
 	git for-each-repo --config=run.key commit --allow-empty -m "ran" &&
 	git -C one log -1 --pretty=format:%s >message &&
 	grep ran message &&
@@ -22,6 +23,7 @@ test_expect_success 'run based on configured value' '
 	grep ran message &&
 	git -C ~/four log -1 --pretty=format:%s >message &&
 	grep ran message &&
+
 	git for-each-repo --config=run.key -- commit --allow-empty -m "ran again" &&
 	git -C one log -1 --pretty=format:%s >message &&
 	grep again message &&
@@ -30,7 +32,17 @@ test_expect_success 'run based on configured value' '
 	git -C three log -1 --pretty=format:%s >message &&
 	grep again message &&
 	git -C ~/four log -1 --pretty=format:%s >message &&
-	grep again message
+	grep again message &&
+
+	git -C three for-each-repo --config=run.key -- commit --allow-empty -m "ran from worktree" &&
+	git -C one log -1 --pretty=format:%s >message &&
+	grep worktree message &&
+	git -C two log -1 --pretty=format:%s >message &&
+	! grep worktree message &&
+	git -C three log -1 --pretty=format:%s >message &&
+	grep worktree message &&
+	git -C ~/four log -1 --pretty=format:%s >message &&
+	grep worktree message
 '
 
 test_expect_success 'do nothing on empty config' '