fix: stop swallowing characters in indented heredoc (#1576)

Fixes #1543

Author: czosel

package.json

@@ -47,7 +47,8 @@
     "test": "jest",
     "prepublishOnly": "yarpm run build-standalone && cross-env RUN_STANDALONE_TESTS=true yarpm test",
     "prettier": "prettier --plugin=. --parser=php",
-    "build-standalone": "rollup -c build/rollup.config.js"
+    "build-standalone": "rollup -c build/rollup.config.js",
+    "debug": "node --inspect-brk node_modules/.bin/jest --runInBand"
   },
   "jest": {
     "projects": [

src/printer.js

@@ -2795,7 +2795,11 @@ function printNode(path, options, print) {
           linebreak,
           node.raw
             .split(/\r?\n/g)
-            .map((s) => s.substring(closingTagIndentation))
+            .map((s, i) =>
+              i > 0 || node.loc.start.column === 0
+                ? s.substring(closingTagIndentation)
+                : s
+            )
         );
       }