1 files changed, 42 insertions, 0 deletions
diff --git a/tests/regression.rs b/tests/regression.rs
new file mode 100644
index 0000000..c2d2c12
--- /dev/null
+++ b/tests/regression.rs
@@ -0,0 +1,42 @@
+use regex_automata::{dense, DFA};
+
+// A regression test for checking that minimization correctly translates
+// whether a state is a match state or not. Previously, it was possible for
+// minimization to mark a non-matching state as matching.
+#[test]
+fn minimize_sets_correct_match_states() {
+    let pattern =
+        // This is a subset of the grapheme matching regex. I couldn't seem
+        // to get a repro any smaller than this unfortunately.
+        r"(?x)
+            (?:
+                \p{gcb=Prepend}*
+                (?:
+                    (?:
+                        (?:
+                            \p{gcb=L}*
+                            (?:\p{gcb=V}+|\p{gcb=LV}\p{gcb=V}*|\p{gcb=LVT})
+                            \p{gcb=T}*
+                        )
+                        |
+                        \p{gcb=L}+
+                        |
+                        \p{gcb=T}+
+                    )
+                    |
+                    \p{Extended_Pictographic}
+                    (?:\p{gcb=Extend}*\p{gcb=ZWJ}\p{Extended_Pictographic})*
+                    |
+                    [^\p{gcb=Control}\p{gcb=CR}\p{gcb=LF}]
+                )
+                [\p{gcb=Extend}\p{gcb=ZWJ}\p{gcb=SpacingMark}]*
+            )
+        ";
+
+    let dfa = dense::Builder::new()
+        .minimize(true)
+        .anchored(true)
+        .build(pattern)
+        .unwrap();
+    assert_eq!(None, dfa.find(b"\xE2"));
+}