From a30080a87fed8137e7bc00ba627c5e7ffd68ce28 Mon Sep 17 00:00:00 2001
From: mattirn <matti.rintanikkola@gmail.com>
Date: Tue, 8 Sep 2020 22:57:24 +0200
Subject: [PATCH] DefaultParser: ArrayIndexOutOfBoundsException, fixes #567

---
 .../test/java/org/jline/example/Example.java  |  5 ++-
 .../org/jline/reader/impl/DefaultParser.java  | 41 ++++++++++---------
 .../completer/StringsCompleterTest.java       | 16 +++++++-
 3 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/builtins/src/test/java/org/jline/example/Example.java b/builtins/src/test/java/org/jline/example/Example.java
index da0b969ff..791779389 100644
--- a/builtins/src/test/java/org/jline/example/Example.java
+++ b/builtins/src/test/java/org/jline/example/Example.java
@@ -160,7 +160,10 @@ public static void main(String[] args) throws IOException {
                         completer = new Completers.FileNameCompleter();
                         break;
                     case "simple":
-                        completer = new StringsCompleter("foo", "bar", "baz");
+                        DefaultParser p3 = new DefaultParser();
+                        p3.setEscapeChars(new char[]{});
+                        parser = p3;
+                        completer = new StringsCompleter("foo", "bar", "baz", "pip pop");
                         break;
                     case "quotes":
                         DefaultParser p = new DefaultParser();
diff --git a/reader/src/main/java/org/jline/reader/impl/DefaultParser.java b/reader/src/main/java/org/jline/reader/impl/DefaultParser.java
index 36faa7ad7..69f4499dc 100644
--- a/reader/src/main/java/org/jline/reader/impl/DefaultParser.java
+++ b/reader/src/main/java/org/jline/reader/impl/DefaultParser.java
@@ -613,25 +613,28 @@ public CharSequence escape(CharSequence candidate, boolean complete) {
                 }
             }
             if (escapeChars != null) {
-                // Completion is protected by an opening quote:
-                // Delimiters (spaces) don't need to be escaped, nor do other quotes, but everything else does.
-                // Also, close the quote at the end
-                if (openingQuote != null) {
-                    needToBeEscaped = i -> isRawEscapeChar(sb.charAt(i)) || String.valueOf(sb.charAt(i)).equals(openingQuote);
-                }
-                // Completion is protected by middle quotes:
-                // Delimiters (spaces) don't need to be escaped, nor do quotes, but everything else does.
-                else if (middleQuotes) {
-                    needToBeEscaped = i -> isRawEscapeChar(sb.charAt(i));
-                }
-                // No quote protection, need to escape everything: delimiter chars (spaces), quote chars
-                // and escapes themselves
-                else {
-                    needToBeEscaped = i -> isDelimiterChar(sb, i) || isRawEscapeChar(sb.charAt(i)) || isRawQuoteChar(sb.charAt(i));
-                }
-                for (int i = 0; i < sb.length(); i++) {
-                    if (needToBeEscaped.test(i)) {
-                        sb.insert(i++, escapeChars[0]);
+                if (escapeChars.length > 0) {
+                    // Completion is protected by an opening quote:
+                    // Delimiters (spaces) don't need to be escaped, nor do other quotes, but everything else does.
+                    // Also, close the quote at the end
+                    if (openingQuote != null) {
+                        needToBeEscaped = i -> isRawEscapeChar(sb.charAt(i)) || String.valueOf(sb.charAt(i)).equals(openingQuote);
+                    }
+                    // Completion is protected by middle quotes:
+                    // Delimiters (spaces) don't need to be escaped, nor do quotes, but everything else does.
+                    else if (middleQuotes) {
+                        needToBeEscaped = i -> isRawEscapeChar(sb.charAt(i));
+                    }
+                    // No quote protection, need to escape everything: delimiter chars (spaces), quote chars
+                    // and escapes themselves
+                    else {
+                        needToBeEscaped = i -> isDelimiterChar(sb, i) || isRawEscapeChar(sb.charAt(i))
+                                || isRawQuoteChar(sb.charAt(i));
+                    }
+                    for (int i = 0; i < sb.length(); i++) {
+                        if (needToBeEscaped.test(i)) {
+                            sb.insert(i++, escapeChars[0]);
+                        }
                     }
                 }
             } else if (openingQuote == null && !middleQuotes) {
diff --git a/reader/src/test/java/org/jline/reader/completer/StringsCompleterTest.java b/reader/src/test/java/org/jline/reader/completer/StringsCompleterTest.java
index d5264de9e..5d21ca848 100644
--- a/reader/src/test/java/org/jline/reader/completer/StringsCompleterTest.java
+++ b/reader/src/test/java/org/jline/reader/completer/StringsCompleterTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002-2016, the original author or authors.
+ * Copyright (c) 2002-2020, the original author or authors.
  *
  * This software is distributable under the BSD license. See the terms of the
  * BSD license in the documentation provided with this software.
@@ -47,6 +47,20 @@ public void escapeCharsNull() throws Exception {
         assertBuffer("bar'f", new TestBuffer("bar'f").tab());
     }
 
+    @Test
+    public void escapeCharsEmpty() throws Exception {
+        DefaultParser dp = (DefaultParser) reader.getParser();
+        dp.setEscapeChars(new char[]{});
+        reader.setVariable(LineReader.ERRORS, 0);
+        reader.setParser(dp);
+        reader.setCompleter(new StringsCompleter("foo bar", "bar"));
+
+        assertBuffer("foo bar ", new TestBuffer("f").tab());
+        assertBuffer("'foo bar' ", new TestBuffer("'f").tab());
+        assertBuffer("foo'b", new TestBuffer("foo'b").tab());
+        assertBuffer("bar'f", new TestBuffer("bar'f").tab());
+    }
+
     @Test
     public void escapeChars() throws Exception {
         DefaultParser dp = (DefaultParser) reader.getParser();