Encode the shr tests files with trailing white space

.gitattributes

@@ -33,9 +33,6 @@ test/etags/html-src/algrthms.html whitespace=cr-at-eol
 # The upstream maintainer does not want to remove trailing whitespace.
 doc/misc/texinfo.tex -whitespace=blank-at-eol
 
-# The shr test files can have trailing whitespace.
-test/data/shr/*.txt -whitespace=blank-at-eol
-
 # Some files should not be treated as text when diffing or merging.
 *.cur binary
 *.gpg binary

test/data/shr/li-empty.txt

@@ -1,3 +1,3 @@
-1 
-2 
-3 
+1%20
+2%20
+3%20

test/lisp/net/shr-tests.el

@@ -36,6 +36,9 @@
       (cons (buffer-substring-no-properties (point-min) (point-max))
             (with-temp-buffer
               (insert-file-contents (format "data/shr/%s.txt" name))
+              (while (re-search-forward "%\\([0-9A-F][0-9A-F]\\)" nil t)
+                (replace-match (string (string-to-number (match-string 1) 16))
+                               t t))
               (buffer-string))))))
 
 (ert-deftest rendering ()