From 50938f3797c822c515ff9454184b8ed7a6ce0124 Mon Sep 17 00:00:00 2001
From: Liumeo <liumeo@pku.edu.cn>
Date: Sun, 23 Jan 2022 20:50:08 -0500
Subject: [PATCH] FIX REPL tab at beginning of line should indent not complete
 (#2125)

---
 docs/project/changelog.md  | 3 +++
 src/templates/console.html | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/docs/project/changelog.md b/docs/project/changelog.md
index 3956dddf2..225779756 100644
--- a/docs/project/changelog.md
+++ b/docs/project/changelog.md
@@ -36,6 +36,9 @@ substitutions:
   improved with some context information.
   {pr}`2121`
 
+- {{Enhancement}} Pressing TAB in REPL no longer triggers completion when input
+  is whitespace. {pr}`2125`
+
 ## Version 0.19.0
 
 _January 10, 2021_
diff --git a/src/templates/console.html b/src/templates/console.html
index c5c3ef029..3fc16ee38 100644
--- a/src/templates/console.html
+++ b/src/templates/console.html
@@ -133,6 +133,15 @@
               term.set_command("");
               term.set_prompt(ps1);
             },
+            "TAB": (event, original) => {
+              const command = term.before_cursor();
+              // Disable completion for whitespaces.
+              if (command.trim() === "") {
+                term.insert("\t");
+                return false;
+              }
+              return original(event);
+            }
           },
         });
         window.term = term;