From 740289bf02c9bea54f75b702f62862c62c62672b Mon Sep 17 00:00:00 2001
From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date: Thu, 21 Mar 2024 15:55:48 +0900
Subject: [PATCH] Merge StringIO 3.0.1.1

---
 ext/stringio/stringio.c        |  2 +-
 test/stringio/test_stringio.rb | 27 ++++++++++++++++++++++-----
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index f537054b5d..946ae06da4 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -833,7 +833,7 @@ strio_unget_bytes(struct StringIO *ptr, const char *cp, long cl)
     len = RSTRING_LEN(str);
     rest = pos - len;
     if (cl > pos) {
-	long ex = (rest < 0 ? cl-pos : cl+rest);
+	long ex = cl - (rest < 0 ? pos : len);
 	rb_str_modify_expand(str, ex);
 	rb_str_set_len(str, len + ex);
 	s = RSTRING_PTR(str);
diff --git a/test/stringio/test_stringio.rb b/test/stringio/test_stringio.rb
index f5169f641a..c055b901e3 100644
--- a/test/stringio/test_stringio.rb
+++ b/test/stringio/test_stringio.rb
@@ -693,6 +693,15 @@ def test_ungetc_padding
     assert_equal("b""\0""a", s.string)
   end
 
+  def test_ungetc_fill
+    count = 100
+    s = StringIO.new
+    s.print 'a' * count
+    s.ungetc('b' * (count * 5))
+    assert_equal((count * 5), s.string.size)
+    assert_match(/\Ab+\z/, s.string)
+  end
+
   def test_ungetbyte_pos
     b = '\\b00010001 \\B00010001 \\b1 \\B1 \\b000100011'
     s = StringIO.new( b )
@@ -718,6 +727,15 @@ def test_ungetbyte_padding
     assert_equal("b""\0""a", s.string)
   end
 
+  def test_ungetbyte_fill
+    count = 100
+    s = StringIO.new
+    s.print 'a' * count
+    s.ungetbyte('b' * (count * 5))
+    assert_equal((count * 5), s.string.size)
+    assert_match(/\Ab+\z/, s.string)
+  end
+
   def test_frozen
     s = StringIO.new
     s.freeze
@@ -760,18 +778,17 @@ def test_new_block_warning
   end
 
   def test_overflow
-    skip if RbConfig::SIZEOF["void*"] > RbConfig::SIZEOF["long"]
+    return if RbConfig::SIZEOF["void*"] > RbConfig::SIZEOF["long"]
     limit = (1 << (RbConfig::SIZEOF["void*"]*8-1)) - 0x10
     assert_separately(%w[-rstringio], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;
       limit = #{limit}
       ary = []
-      while true
+      begin
         x = "a"*0x100000
         break if [x].pack("p").unpack("i!")[0] < 0
         ary << x
-        skip if ary.size > 100
-      end
+      end while ary.size <= 100
       s = StringIO.new(x)
       s.gets("xxx", limit)
       assert_equal(0x100000, s.pos)