From 14e1739ff3ec81c9ea87a8aba03393f0bf0433a7 Mon Sep 17 00:00:00 2001 From: Jeremy Evans Date: Tue, 2 Mar 2021 12:17:23 -0800 Subject: [ruby/irb] Make save-history extension safe for concurrent use This makes the save-history extension check for modifications to the history file before saving it. If the history file was modified after the history was loaded and before it was saved, append only the new history lines to the history file. This can result in more lines in the history file than SAVE_HISTORY allows. However, that will be fixed the next time irb is run and the history is saved. Fixes [Bug #13654] https://github.com/ruby/irb/commit/041ef53845 --- lib/irb/ext/save-history.rb | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) (limited to 'lib/irb') diff --git a/lib/irb/ext/save-history.rb b/lib/irb/ext/save-history.rb index ac358c8ccb..7acaebe36a 100644 --- a/lib/irb/ext/save-history.rb +++ b/lib/irb/ext/save-history.rb @@ -81,6 +81,8 @@ module IRB end } end + @loaded_history_lines = history.size + @loaded_history_mtime = File.mtime(history_file) end end @@ -105,12 +107,20 @@ module IRB raise end - open(history_file, "w:#{IRB.conf[:LC_MESSAGES].encoding}", 0600) do |f| + if File.exist?(history_file) && @loaded_history_mtime && + File.mtime(history_file) != @loaded_history_mtime + history = history[@loaded_history_lines..-1] + append_history = true + end + + open(history_file, "#{append_history ? 'a' : 'w'}:#{IRB.conf[:LC_MESSAGES].encoding}", 0600) do |f| hist = history.map{ |l| l.split("\n").join("\\\n") } - begin - hist = hist.last(num) if hist.size > num and num > 0 - rescue RangeError # bignum too big to convert into `long' - # Do nothing because the bignum should be treated as inifinity + unless append_history + begin + hist = hist.last(num) if hist.size > num and num > 0 + rescue RangeError # bignum too big to convert into `long' + # Do nothing because the bignum should be treated as inifinity + end end f.puts(hist) end -- cgit v1.2.3