libexpr: Fix prim_replaceStrings() to work on an empty source string

Otherwise, running e.g.

nix-instantiate --eval -E --strict 'builtins.replaceStrings [""] ["X"] "abc"'

would just hang in an infinite loop.

Found by afl-fuzz.

First attempt of this was reverted in e2d71bd186 because it caused
another infinite loop, which is fixed now and a test added.
This commit is contained in:
Tuomas Tynkkynen 2018-02-19 17:52:33 +02:00
parent 24ec750003
commit 77e9e1ed91
3 changed files with 18 additions and 4 deletions

View file

@ -5,4 +5,7 @@ with builtins;
(replaceStrings ["oo"] ["u"] "foobar")
(replaceStrings ["oo" "a"] ["a" "oo"] "foobar")
(replaceStrings ["oo" "oo"] ["u" "i"] "foobar")
(replaceStrings [""] ["X"] "abc")
(replaceStrings [""] ["X"] "")
(replaceStrings ["-"] ["_"] "a-b")
]