Fix docs on test environment and add a test

Fixes bazelbuild#1126.

--
MOS_MIGRATED_REVID=120707955

site/docs/test-encyclopedia.html

@@ -203,7 +203,7 @@ <h3>Initial Conditions</h3>
     <tr><td><code>LOGNAME</code></td><td>value of <code>$USER</code></td><td>required</td></tr>
 
     <tr><td><code>PATH</code></td><td><code>/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.</code></td><td>recommended</td></tr>
-    <tr><td><code>PWD</code></td><td><code>$TEST_SRCDIR</code></td><td>recommended</td></tr>
+    <tr><td><code>PWD</code></td><td><code>$TEST_SRCDIR/<i>workspace-name</i></code></td><td>recommended</td></tr>
     <tr><td><code>SHLVL</code></td><td><code>2</code></td><td>recommended</td></tr>
     <tr><td><code>TEST_PREMATURE_EXIT_FILE</code></td><td>absolute path to a private file in a writable directory (used for catching calls to exit())</td><td>optional</td></tr>
     <tr><td><code>TEST_RANDOM_SEED</code></td><td>See <a href="bazel-user-manual.html#other_options_for_blaze_test">this table</a>.</td><td>optional</td></tr>
@@ -222,13 +222,16 @@ <h3>Initial Conditions</h3>
 
     <tr><td><code>USER</code></td><td>value of <code>getpwuid(getuid())-&gt;pw_name</code></td><td>required</td></tr>
 
+    <tr><td><code>XML_OUTPUT_FILE</code></td><td>Location of the <code>ANT</code>-like XML output file</td><td>optional</td></tr>
+    <tr><td><code>TEST_WORKSPACE</code></td><td>the local repository's workspace name</td><td>optional</td></tr>
+
   </tbody>
 </table>
 <br>
 <p>The environment may contain additional entries.  Tests should not depend on the
 presence, absence, or value of any environment variable not listed above.</p>
 
-<p>The initial working directory shall be <code>$TEST_SRCDIR</code>.</p>
+<p>The initial working directory shall be <code>$TEST_SRCDIR/$TEST_WORKSPACE</code>.</p>
 <p> The current process id, process group id, session id, and parent process
 id are unspecified.  The process may or may not be a process group leader or a
 session leader.  The process may or may not have a controlling terminal.  The

src/test/shell/bazel/bazel_test_test.sh

@@ -115,6 +115,31 @@ EOF
   expect_log "TEST_TMPDIR=$TEST_TMPDIR"
 }
 
+function test_env_vars() {
+  cat > WORKSPACE <<EOF
+workspace(name = "bar")
+EOF
+  mkdir -p foo
+  cat > foo/testenv.sh <<'EOF'
+#!/bin/bash
+echo "pwd: $PWD"
+echo "src: $TEST_SRCDIR"
+echo "ws: $TEST_WORKSPACE"
+EOF
+  chmod +x foo/testenv.sh
+  cat > foo/BUILD <<EOF
+sh_test(
+    name = "foo",
+    srcs = ["testenv.sh"],
+)
+EOF
+
+  bazel test --test_output=all //foo &> $TEST_log || fail "Test failed"
+  expect_log "pwd: .*/foo.runfiles/bar$"
+  expect_log "src: .*/foo.runfiles$"
+  expect_log "ws: bar$"
+}
+
 function test_run_under_label_with_options() {
   mkdir -p testing run || fail "mkdir testing run failed"
   cat <<EOF > run/BUILD