[SR-11281] Swift REPL: Cannot access command history

[swift-ci]

Previous ID	SR-11281
Radar	None
Original Reporter	palle (JIRA User)
Type	Bug

Environment

Apple Swift version 5.1 (swiftlang-1100.0.266.1 clang-1100.0.32.1)

Additional Detail from JIRA

Votes	4
Component/s	LLDB for Swift
Labels	Bug
Assignee	@JDevlieghere
Priority	Medium

md5: 4c6fb2b8a68d33bbf6440b90abeea702

Issue Description:

Since Swift 5.1, it is no longer possible to go through the command history in the REPL by pressing the up/down arrow keys. It is only possible to recall the most recent command.

Steps to reproduce:

1. Open a terminal

2. Type in swift and press return to start the REPL

3. Type in the following:

   func foo() {}
   func bar() {} 

4. Press the up arrow key twice

Expected results:

The current input should be

func foo() {} 

Actual results:

The current line input is

func bar() {} 

Further notes:

Pressing the down arrow after pressing the up arrow results in a command from a previous sessions being shown.

[jepers]

Pressing tab for code completion is not working anymore either.

[benrimmington]

REPL history (up/down arrows) and code completion (tab key) appear to be fixed in the Swift 5.2 REPL (after installing Xcode 11.4).

LLDB history (i.e. :help command history) doesn't work in REPL mode. For example, :command history prints nothing, and :-2 in history.