fix: reset line offset when empty line encountered

Author: galaxian85

lib/rules_block/blockquote.js

@@ -279,7 +279,11 @@ module.exports = function blockquote(state, startLine, endLine, silent) {
     const lineNumber = i + startLine;
     if (state.lineOffsets[lineNumber] === null) {
       state.lineOffsets[lineNumber] = totalLineOffset;
-      totalLineOffset += calcLineOffset(state, lineNumber);
+      if (isNotEmptyLine(state, lineNumber)) {
+        totalLineOffset += calcLineOffset(state, lineNumber);
+      } else {
+        totalLineOffset = 0;
+      }
     }
 
     state.bMarks[lineNumber] = oldBMarks[i];
@@ -296,3 +300,10 @@ function calcLineOffset (state, lineNumber) {
   const previousLineEnd = state.eMarks[lineNumber - 1] + 1 || 0;
   return state.bMarks[lineNumber] - previousLineEnd;
 }
+
+function isNotEmptyLine (state, lineNumber) {
+  return (
+    state.bMarks[lineNumber] + state.tShift[lineNumber] <
+    state.eMarks[lineNumber]
+  )
+}