Fix emphasis not closing when followed by CJK character

lib/rules_inline/state_inline.mjs

@@ -3,6 +3,17 @@
 import Token from '../token.mjs'
 import { isWhiteSpace, isPunctChar, isMdAsciiPunct } from '../common/utils.mjs'
 
+// Check if the character is a CJK character.
+//
+// ranges:
+// - 0x4E00 - 0x9FFF : CJK Unified Ideographs
+// - 0xAC00 - 0xD7A3 : Hangul Syllables
+//
+function isCJK (code) {
+  return (code >= 0x4E00 && code <= 0x9FFF) ||
+         (code >= 0xAC00 && code <= 0xD7A3)
+}
+
 function StateInline (src, md, env, outTokens) {
   this.src = src
   this.env = env
@@ -106,10 +117,12 @@ StateInline.prototype.scanDelims = function (start, canSplitWord) {
   const isLastWhiteSpace = isWhiteSpace(lastChar)
   const isNextWhiteSpace = isWhiteSpace(nextChar)
 
+  const isNextCJK = isCJK(nextChar)
+
   const left_flanking =
     !isNextWhiteSpace && (!isNextPunctChar || isLastWhiteSpace || isLastPunctChar)
   const right_flanking =
-    !isLastWhiteSpace && (!isLastPunctChar || isNextWhiteSpace || isNextPunctChar)
+    !isLastWhiteSpace && (!isLastPunctChar || isNextWhiteSpace || isNextPunctChar || isNextCJK)
 
   const can_open  = left_flanking  && (canSplitWord || !right_flanking || isLastPunctChar)
   const can_close = right_flanking && (canSplitWord || !left_flanking  || isNextPunctChar)