[ruby/irb] Make history infinite if set SAVE_HISTORY to negative

https://github.com/ruby/irb/commit/824473e880

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/irb/ext/save-history.rb b/lib/irb/ext/save-history.rb
index 2d9808259d..3a0703a72c 100644
--- a/lib/irb/ext/save-history.rb
+++ b/lib/irb/ext/save-history.rb
@@ -89,7 +89,7 @@ module IRB
     def save_history
       return unless self.class.const_defined?(:HISTORY)
       history = self.class::HISTORY
-      if num = IRB.conf[:SAVE_HISTORY] and (num = num.to_i) > 0
+      if num = IRB.conf[:SAVE_HISTORY] and (num = num.to_i) != 0
         if history_file = IRB.conf[:HISTORY_FILE]
           history_file = File.expand_path(history_file)
         end
@@ -110,7 +110,7 @@ module IRB
         open(history_file, "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
+            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