Refuse to reload session unless test id and version match

src/jat.sh.skel

@@ -590,6 +590,8 @@ jat__sinit() {
     # Load active session if found; otherwise initialize new one.
     #
     local reload=false
+    local old_test_id
+    local old_test_version
     mkdir -p "$JAT__DIR" \
      || die "could not initialize JAT__DIR: $JAT__DIR"
     __JAT__SDIR=$JAT__DIR/session
@@ -600,6 +602,16 @@ jat__sinit() {
     export JAT__YLOG
     debug -v reload __JAT__SDIR
     if $reload; then
+        old_test_id=$(__jat__sd_keyr test_id)
+        old_test_version=$(__jat__sd_keyr test_version)
+        test "$old_test_id" == "$JAT__TEST_ID" || {
+            warn -v JAT__TEST_ID old_test_id
+            die "cannot reload session of different test"
+        }
+        test "$old_test_version" == "$JAT__TEST_VERSION" || {
+            warn -v JAT__TEST_VERSION old_test_version
+            die "cannot reload session of different test version"
+        }
         __jat__log_event SINFO "reloaded session" "" \
             -- \
             "JAT__LOG_FMT=$__JAT__LOG_FMT" \
@@ -617,6 +629,8 @@ jat__sinit() {
             echo "start: $(__jat__newstamp)"
             echo "events:"
         } | __jat__writelog
+        __jat__sd_keyw test_id "$JAT__TEST_ID"
+        __jat__sd_keyw test_version "$JAT__TEST_VERSION"
         __jat__pdummy
         __jat__log_event SINFO "started new session"
         __jat__show_sinitn