py3: replace s[-1] with s.endswith() in eol handling

contrib/python3-whitelist

@@ -123,6 +123,7 b' test-encoding.t'
 test-eol-add.t
 test-eol-clone.t
 test-eol-hook.t
+test-eol-patch.t
 test-eol-tag.t
 test-eol-update.t
 test-excessive-merge.t
@@ -199,6 +200,7 b' test-http-clone-r.t'
 test-http.t
 test-hybridencode.py
 test-identify.t
+test-import-bypass.t
 test-import-merge.t
 test-import-unknown.t
 test-import.t

hgext/eol.py

@@ -142,7 +142,7 b' def tolf(s, params, ui, **kwargs):'
     if ui.configbool('eol', 'only-consistent') and inconsistenteol(s):
         return s
     if (ui.configbool('eol', 'fix-trailing-newline')
-        and s and s[-1] != '\n'):
+        and s and not s.endswith('\n')):
         s = s + '\n'
     return util.tolf(s)
 
@@ -153,7 +153,7 b' def tocrlf(s, params, ui, **kwargs):'
     if ui.configbool('eol', 'only-consistent') and inconsistenteol(s):
         return s
     if (ui.configbool('eol', 'fix-trailing-newline')
-        and s and s[-1] != '\n'):
+        and s and not s.endswith('\n')):
         s = s + '\n'
     return util.tocrlf(s)
 

mercurial/patch.py

@@ -707,7 +707,7 b' class patchfile(object):'
         if self.eolmode != 'strict' and eol and eol != '\n':
             rawlines = []
             for l in lines:
-                if l and l[-1] == '\n':
+                if l and l.endswith('\n'):
                     l = l[:-1] + eol
                 rawlines.append(l)
             lines = rawlines