[ruby/net-http] Update the content-length heading when decoding bodies

Previously, the content-encoding header was removed and the body
was modified, but the content-length header was not modified,
resulting in the content-length header not matching the body
length.

Don't delete content-length before yielding inflate body, as that
causes a switch to read the entire body instead of reading in
chunks.

Fixes [Bug #16672]

ruby/net-http@58284e9710

Co-authored-by: st0012 <stan001212@gmail.com>

lib/net/http/response.rb

@@ -431,6 +431,9 @@ def inflater # :nodoc:
       ensure
         begin
           inflate_body_io.finish
+          if self['content-length']
+            self['content-length'] = inflate_body_io.bytes_inflated.to_s
+          end
         rescue => err
           # Ignore #finish's error if there is an exception from yield
           raise err if success
@@ -532,6 +535,14 @@ def finish
       @inflate.finish
     end
 
+    ##
+    # The number of bytes inflated, used to update the Content-Length of
+    # the response.
+
+    def bytes_inflated
+      @inflate.total_out
+    end
+
     ##
     # Returns a Net::ReadAdapter that inflates each read chunk into +dest+.
     #

test/net/http/test_httpresponse.rb

@@ -362,9 +362,11 @@ def test_read_body_content_encoding_deflate
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal '5', res['content-length']
       assert_equal 'hello', body
     else
       assert_equal 'deflate', res['content-encoding']
+      assert_equal '13', res['content-length']
       assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15", body
     end
   end
@@ -390,9 +392,11 @@ def test_read_body_content_encoding_deflate_uppercase
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal '5', res['content-length']
       assert_equal 'hello', body
     else
       assert_equal 'DEFLATE', res['content-encoding']
+      assert_equal '13', res['content-length']
       assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15", body
     end
   end
@@ -423,9 +427,11 @@ def test_read_body_content_encoding_deflate_chunked
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal 'hello', body
     else
       assert_equal 'deflate', res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15", body
     end
   end
@@ -450,6 +456,7 @@ def test_read_body_content_encoding_deflate_disabled
     end
 
     assert_equal 'deflate', res['content-encoding'], 'Bug #7831'
+    assert_equal '13', res['content-length']
     assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15", body, 'Bug #7381'
   end
 
@@ -473,9 +480,11 @@ def test_read_body_content_encoding_deflate_no_length
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal 'hello', body
     else
       assert_equal 'deflate', res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15\r\n", body
     end
   end
@@ -523,9 +532,11 @@ def test_read_body_content_encoding_deflate_empty_body
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal '0', res['content-length']
       assert_equal '', body
     else
       assert_equal 'deflate', res['content-encoding']
+      assert_equal '0', res['content-length']
       assert_equal '', body
     end
   end
@@ -549,9 +560,11 @@ def test_read_body_content_encoding_deflate_empty_body_no_length
 
     if Net::HTTP::HAVE_ZLIB
       assert_equal nil, res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal '', body
     else
       assert_equal 'deflate', res['content-encoding']
+      assert_equal nil, res['content-length']
       assert_equal '', body
     end
   end