Fixed shebang formatting (PY-12775).

python/src/com/jetbrains/python/formatter/PyPreFormatProcessor.java

@@ -84,6 +84,9 @@ public class PyPreFormatProcessor implements PreFormatProcessor {
       String text = element.getText();
       int commentStart = text.indexOf('#');
       if (commentStart != -1 && (commentStart + 1) < text.length()) {
+        if (text.charAt(commentStart+1) == '!') {
+          return; //shebang
+        }
         String commentText = StringUtil.trimLeading(text.substring(commentStart + 1));
 
         String newText = "# " + commentText;

python/testData/formatter/shebang.py

@@ -0,0 +1 @@
+#!/usr/bin/python3

python/testData/formatter/shebang_after.py

@@ -0,0 +1 @@
+#!/usr/bin/python3

python/testSrc/com/jetbrains/python/PyFormatterTest.java

@@ -398,6 +398,10 @@ public class PyFormatterTest extends PyTestCase {
     doTest();
   }
 
+  public void testShebang() { //PY-12775
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }