[pypy-commit] pypy default: Revert 3b13b7c4c388 through 029ef1dd4a1a: this may look like a good

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r54059:516cbe7d60c0
Date: 2012-03-29 13:15 +0200
http://bitbucket.org/pypy/pypy/changeset/516cbe7d60c0/

Log:	Revert 3b13b7c4c388 through 029ef1dd4a1a: this may look like a good
	idea, but it creates a new path for the JIT, which is problematic in
	some cases. Reverting unless further discussion justifies it.

diff --git a/pypy/rpython/lltypesystem/rstr.py b/pypy/rpython/lltypesystem/rstr.py
--- a/pypy/rpython/lltypesystem/rstr.py
+++ b/pypy/rpython/lltypesystem/rstr.py
@@ -765,8 +765,7 @@
     def _ll_stringslice(s1, start, stop):
         lgt = stop - start
         assert start >= 0
-        if lgt <= 0:
-            return s1.empty()
+        assert lgt >= 0
         newstr = s1.malloc(lgt)
         s1.copy_contents(s1, newstr, start, 0, lgt)
         return newstr
diff --git a/pypy/rpython/ootypesystem/rstr.py b/pypy/rpython/ootypesystem/rstr.py
--- a/pypy/rpython/ootypesystem/rstr.py
+++ b/pypy/rpython/ootypesystem/rstr.py
@@ -222,8 +222,6 @@
         length = s.ll_strlen()
         if stop > length:
             stop = length
-        if start > stop:
-            start = stop
         return s.ll_substring(start, stop-start)
 
     def ll_stringslice_minusone(s):
diff --git a/pypy/rpython/test/test_rstr.py b/pypy/rpython/test/test_rstr.py
--- a/pypy/rpython/test/test_rstr.py
+++ b/pypy/rpython/test/test_rstr.py
@@ -477,11 +477,7 @@
             s1 = s[:3]
             s2 = s[3:]
             s3 = s[3:10]
-            s4 = s[42:44]
-            return (s1+s2 == s and
-                    s2+s1 == const('lohel') and
-                    s1+s3 == s and
-                    s4 == const(''))
+            return s1+s2 == s and s2+s1 == const('lohel') and s1+s3 == s
         res = self.interpret(fn, [0])
         assert res