Add test showing history bug (#899)

Change-Id: history_bug

Author: LMG

tests/filter/graphql_history.t

@@ -0,0 +1,44 @@
+  $ export TESTTMP=${PWD}
+
+  $ cd ${TESTTMP}
+  $ git init -q repo 1> /dev/null
+  $ cd repo
+
+  $ echo contents0 > file1
+  $ git add .
+  $ git commit -m "add file1" 1> /dev/null
+  $ echo contents2 > file2
+  $ git add .
+  $ git commit -m "add file2" 1> /dev/null
+  $ mkdir ws
+  $ cat > ws/workspace.josh <<EOF
+  > ::file2
+  > EOF
+  $ git add .
+  $ git commit -m "add ws" 1> /dev/null
+
+  $ cat > query <<EOF
+  > query {
+  >   rev(at: "HEAD", filter: ":workspace=ws") {
+  >     history(limit: 1) {
+  >       summary
+  >     }
+  >   }
+  > }
+  > EOF
+
+  $ josh-filter -g "$(cat query)"
+  {"rev":{"history":[{"summary":"add ws"}]}}
+
+  $ cat > query2 <<EOF
+  > query {
+  >   rev(at: "HEAD", filter: ":workspace=ws") {
+  >     history(limit: 2) {
+  >       summary
+  >     }
+  >   }
+  > }
+  > EOF
+
+  $ josh-filter -g "$(cat query2)"
+  null