From b26d6c70e0f08050ca23388bb0e8442f73269c73 Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Mon, 23 Nov 2020 11:03:15 -0800
Subject: [PATCH] Detect the premature end of char property in regexp

Default to ONIGERR_INVALID_CHAR_PROPERTY_NAME in
fetch_char_property_to_ctype and only set otherwise if an ending
} is found.

Fixes [Bug #17340]
---
 regparse.c               |  3 +--
 test/ruby/test_regexp.rb | 11 +++++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/regparse.c b/regparse.c
index a96c8c2fa7d673..7639db3bbed668 100644
--- a/regparse.c
+++ b/regparse.c
@@ -4348,7 +4348,7 @@ fetch_char_property_to_ctype(UChar** src, UChar* end, ScanEnv* env)
   OnigEncoding enc = env->enc;
   UChar *prev, *start, *p = *src;
 
-  r = 0;
+  r = ONIGERR_INVALID_CHAR_PROPERTY_NAME;
   start = prev = p;
 
   while (!PEND) {
@@ -4362,7 +4362,6 @@ fetch_char_property_to_ctype(UChar** src, UChar* end, ScanEnv* env)
       return r;
     }
     else if (c == '(' || c == ')' || c == '{' || c == '|') {
-      r = ONIGERR_INVALID_CHAR_PROPERTY_NAME;
       break;
     }
   }
diff --git a/test/ruby/test_regexp.rb b/test/ruby/test_regexp.rb
index 231fd392d17d0e..220e2b78aee087 100644
--- a/test/ruby/test_regexp.rb
+++ b/test/ruby/test_regexp.rb
@@ -57,6 +57,17 @@ def test_ruby_dev_31309
     assert_equal('Ruby', 'Ruby'.sub(/[^a-z]/i, '-'))
   end
 
+  def test_premature_end_char_property
+    ["\\p{",
+     "\\p{".dup.force_encoding("UTF-8"),
+     "\\p{".dup.force_encoding("US-ASCII")
+    ].each do |string|
+      assert_raise(RegexpError) do
+        Regexp.new(string)
+      end
+    end
+  end
+
   def test_assert_normal_exit
     # moved from knownbug.  It caused core.
     Regexp.union("a", "a")