api: make Regex UnwindSafe again

This commit fixes a regression introduced in 1.1.3 where Regex was no
longer UnwindSafe. The underlying reason is that the new AhoCorasick
type in aho-corasick 0.7 was not UnwindSafe. This has been fixed in
aho-corasick 0.7.4, so all we need to do to fix it is to increase the
minimum aho-corasick version, which we do here.

We also add an oibits test that ensures this particular regression can't
happen again. (Along with testing Send and Sync, which surprisingly did
not have seem to have tests before this.)

Fixes #568

Author: BurntSushi

CHANGELOG.md

@@ -1,3 +1,16 @@
+1.1.4 (2019-03-31)
+==================
+This release fixes a backwards compatibility regression where Regex was no
+longer UnwindSafe. This was caused by the upgrade to aho-corasick 0.7, whose
+AhoCorasick type was itself not UnwindSafe. This has been fixed in aho-corasick
+0.7.4, which we now require.
+
+Bug fixes:
+
+* [BUG #568](https://github.com/rust-lang/regex/pull/568):
+  Fix an API regression where Regex was no longer UnwindSafe.
+
+
 1.1.3 (2019-03-30)
 ==================
 This releases fixes a few bugs and adds a performance improvement when a regex

Cargo.toml

@@ -26,7 +26,7 @@ members = [
 
 [dependencies]
 # For very fast prefix literal matching.
-aho-corasick = "0.7.1"
+aho-corasick = "0.7.3"
 # For skipping along search text quickly when a leading byte is known.
 memchr = "2.0.2"
 # For managing regex caches quickly across multiple threads.

tests/test_default.rs

@@ -85,3 +85,37 @@ fn disallow_octal() {
 fn allow_octal() {
     assert!(regex::RegexBuilder::new(r"\0").octal(true).build().is_ok());
 }
+
+#[test]
+fn oibits() {
+    use std::panic::UnwindSafe;
+    use regex::{Regex, RegexBuilder};
+    use regex::bytes;
+
+    fn assert_send<T: Send>() {}
+    fn assert_sync<T: Sync>() {}
+    fn assert_unwind_safe<T: UnwindSafe>() {}
+
+    assert_send::<Regex>();
+    assert_sync::<Regex>();
+    assert_unwind_safe::<Regex>();
+    assert_send::<RegexBuilder>();
+    assert_sync::<RegexBuilder>();
+    assert_unwind_safe::<RegexBuilder>();
+
+    assert_send::<bytes::Regex>();
+    assert_sync::<bytes::Regex>();
+    assert_unwind_safe::<bytes::Regex>();
+    assert_send::<bytes::RegexBuilder>();
+    assert_sync::<bytes::RegexBuilder>();
+    assert_unwind_safe::<bytes::RegexBuilder>();
+}
+
+// See: https://github.com/rust-lang/regex/issues/568
+#[test]
+fn oibits_regression() {
+    use std::panic;
+    use regex::Regex;
+
+    let _ = panic::catch_unwind(|| Regex::new("a").unwrap());
+}