Fix: indent bug about semicolons

Author: mysticatea

lib/utils/indent-common.js

@@ -1419,14 +1419,25 @@ module.exports.defineVisitor = function create (context, tokenStore, defaultOpti
     // Process semicolons.
     ':statement' (node) {
       const info = offsets.get(tokenStore.getFirstToken(node))
-      const prevToken = tokenStore.getTokenBefore(node)
-      const lastToken = tokenStore.getLastToken(node)
-
-      if (info != null && isSemicolon(prevToken)) {
-        offsets.set(prevToken, info)
+      if (info == null) {
+        return
       }
-      if (info != null && isSemicolon(lastToken)) {
-        offsets.set(lastToken, info)
+
+      // Set to the semicolon of the previous token for semicolon-free style.
+      // E.g.,
+      //   foo
+      //   ;[1,2,3].forEach(f)
+      const tokens = [
+        tokenStore.getTokenBefore(node),
+        tokenStore.getLastToken(node)
+      ].filter(isSemicolon)
+
+      // Set offsets if the semicolon is at beginning of line.
+      for (const token of tokens) {
+        const prevToken = tokenStore.getTokenBefore(token)
+        if (prevToken == null || token.loc.end.line !== prevToken.loc.start.line) {
+          offsets.set(token, info)
+        }
       }
     },
 

tests/fixtures/script-indent/if-statement-04.js

@@ -0,0 +1,4 @@
+/*{}*/
+if (a)
+  b;
+c

tests/fixtures/script-indent/if-statement-05.js

@@ -0,0 +1,6 @@
+/*{}*/
+function wrap() {
+  if (x)
+    this.doSomething();
+  foo
+}