From 4f7fb13f87e10bd2cd89ccf2be70b026032237a7 Mon Sep 17 00:00:00 2001 From: Raphael Isemann Date: Tue, 31 Aug 2021 18:12:51 +0200 Subject: [PATCH] [lldb] Don't save empty expressions in the multiline editor history Right now running `expr` to start the multiline expression editor and then pressing enter causes an empty history empty to be created for the multiline editor. That doesn't seem very useful for users as pressing the 'up' key will now also bring up these empty expressions. I don't think there is ever a use case for recalling a completely empty expression from the history, so instead don't save those entries to the history file and make sure we never recall them when navigating over the expression history. Note: This is actually a Swift downstream patch that got shipped with Apple's LLDB for many years. However, this recently started conflicting with upstream LLDB as D100048 added a test that made sure that empty expression entries don't crash LLDB. Apple's LLDB was never affected by this crash as it never saved empty expressions in the first place. Reviewed By: augusto2112 Differential Revision: https://reviews.llvm.org/D108983 --- lldb/source/Host/common/Editline.cpp | 6 ++++-- .../TestMultilineNavigation.py | 22 ++++++++++++++++------ 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/lldb/source/Host/common/Editline.cpp b/lldb/source/Host/common/Editline.cpp index bcc1743..5bfb612 100644 --- a/lldb/source/Host/common/Editline.cpp +++ b/lldb/source/Host/common/Editline.cpp @@ -1554,8 +1554,10 @@ bool Editline::GetLines(int first_line_number, StringList &lines, interrupted = m_editor_status == EditorStatus::Interrupted; if (!interrupted) { - // Save the completed entry in history before returning - m_history_sp->Enter(CombineLines(m_input_lines).c_str()); + // Save the completed entry in history before returning. Don't save empty + // input as that just clutters the command history. + if (m_input_lines.size() > 1 || !m_input_lines.front().empty()) + m_history_sp->Enter(CombineLines(m_input_lines).c_str()); lines = GetInputAsStringList(); } diff --git a/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py b/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py index 369ae3fb..938934f 100644 --- a/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py +++ b/lldb/test/API/commands/expression/multiline-navigation/TestMultilineNavigation.py @@ -76,22 +76,32 @@ class TestCase(PExpectTest): @skipIfEditlineSupportMissing @expectedFailureAll(oslist=['freebsd'], bugnumber='llvm.org/pr48316') @skipIf(oslist=["linux"], archs=["arm", "aarch64"]) # Randomly fails on buildbot - def test_nav_arrow_up_empty_pr49845(self): - """Tests that navigating with the up arrow doesn't crash.""" + def test_nav_arrow_up_empty(self): + """ + Tests that navigating with the up arrow doesn't crash and skips + empty history entries. + """ self.launch() - # Create an empty history session by only entering a newline. + # Create a real history entry '456' and then follow up with an + # empty entry (that shouldn't be saved). + self.child.sendline("expr") + self.child.expect_exact("terminate with an empty line to evaluate") + self.child.send("456\n\n") + self.expect_prompt() + self.child.sendline("expr") self.child.expect_exact("terminate with an empty line to evaluate") self.child.send("\n") self.expect_prompt() - # Send just the up arrow in the expression evaluator. This should bring up the previous empty expression. + # The up arrow should recall the actual history entry and not the + # the empty entry (as that one shouldn't have been saved). self.child.sendline("expr") self.child.expect_exact("terminate with an empty line to evaluate") self.child.send(self.arrow_up) - self.child.expect_exact("1: ") - self.child.send("\n") + self.child.expect_exact("456") + self.child.send("\n\n") self.expect_prompt() self.quit() -- 2.7.4