[RFC/PoC 3/5] test-lib: add GIT_BUNDLE_DIR setup

[Philip Oakley <philipoakley@iee.email>]

The test system may output a number of documentation bundles containing
test repositories of interest to users, including those explicitly
documented.

Provide a default location for holding those bundles.
As build artefact's this location, along with `.bndl` files, was
ignored in an earlier commit.

This may need further refinement.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
---
 t/test-lib.sh | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 4e45bc7c4f..b18cd8a34e 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -56,6 +56,20 @@ then
 	echo "PANIC: Running in a $TEST_DIRECTORY that doesn't end in '/t'?" >&2
 	exit 1
 fi
+if test -z "$GIT_BUNDLE_DIR"
+then
+	# Similarly, override this to store the documentation bundles subdir
+	# elsewhere
+	GIT_BUNDLE_DIR=$TEST_DIRECTORY/GIT_BUNDLE_DIR
+	if test ! -d "$GIT_BUNDLE_DIR"
+	then
+		mkdir -p "$GIT_BUNDLE_DIR"
+	fi
+elif test ! -d "$GIT_BUNDLE_DIR"
+then
+	echo "PANIC: Your "$GIT_BUNDLE_DIR" doesn't exist!" >&2
+	exit 1
+fi
 
 # Prepend a string to a VAR using an arbitrary ":" delimiter, not
 # adding the delimiter if VAR or VALUE is empty. I.e. a generalized:
-- 
2.38.1.281.g83ef3ded8d