+chkm="main4 main6"
+chkms="main-sub10 main-sub5 main-sub7 main-sub8"
+chkms_sub=$(echo $chkms | multiline | sed 's,^,subdir/,' | fixnl)
+chks="sub1 sub2 sub3 sub9"
+chks_sub=$(echo $chks | multiline | sed 's,^,subdir/,' | fixnl)
+
+# make sure exactly the right set of files ends up in the subproj
+subfiles=$(git ls-files | fixnl)
+check_equal "$subfiles" "$chkms $chks"
+
+# make sure the subproj history *only* contains commits that affect the subdir.
+allchanges=$(git log --name-only --pretty=format:'' | sort | fixnl)
+check_equal "$allchanges" "$chkms $chks"
+