Fix #1413 Can't use `bat` at all! (Error: Use of bat as a pager is disallowed...)

Fixed by implementing the proposal by sharkdp:

* Allow PAGER=bat, but ignore the setting in bat and simply default to
  less. Unless of course, BAT_PAGER or --pager is used to overwrite the
  value of PAGER.

* Disallow the usage of bat within BAT_PAGER and --pager.

1 files changed, 24 insertions, 1 deletions

diff --git a/tests/integration_tests.rs b/tests/integration_tests.rs
index 6128b801..ce44933b 100644
--- a/tests/integration_tests.rs
+++ b/tests/integration_tests.rs
@@ -500,13 +500,36 @@ fn pager_disable() {
 }
 
 #[test]
+fn env_var_pager_value_bat() {
+    bat()
+        .env("PAGER", "bat")
+        .arg("--paging=always")
+        .arg("test.txt")
+        .assert()
+        .success()
+        .stdout(predicate::eq("hello world\n").normalize());
+}
+
+#[test]
+fn env_var_bat_pager_value_bat() {
+    bat()
+        .env("BAT_PAGER", "bat")
+        .arg("--paging=always")
+        .arg("test.txt")
+        .assert()
+        .failure()
+        .stderr(predicate::str::contains("bat as a pager is disallowed"));
+}
+
+#[test]
 fn pager_value_bat() {
     bat()
         .arg("--pager=bat")
         .arg("--paging=always")
         .arg("test.txt")
         .assert()
-        .failure();
+        .failure()
+        .stderr(predicate::str::contains("bat as a pager is disallowed"));
 }
 
 /// We shall use less instead of most if PAGER is used since PAGER