# HG changeset patch
# User igerasim
# Date 1567649348 25200
#      Wed Sep 04 19:09:08 2019 -0700
# Node ID 021d2408e69f06c0588903b8011eadfb7ed36000
# Parent  f016cc0874f03dbeec5e275f45247ee5724acad3
[mq]: 8230365-Pattern-for-a-control-char-matches-non-control-characters

diff --git a/src/java.base/share/classes/java/util/regex/ASCII.java b/src/java.base/share/classes/java/util/regex/ASCII.java
--- a/src/java.base/share/classes/java/util/regex/ASCII.java
+++ b/src/java.base/share/classes/java/util/regex/ASCII.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2000, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -259,6 +259,10 @@
         return isType(ch, WORD);
     }
 
+    static boolean isCntrlId(int ch) {
+        return ((ch-0x3f)|(0x5f-ch)) >= 0;
+    }
+
     static int toDigit(int ch) {
         return (ctype[ch & 0x7F] & 0x3F);
     }
diff --git a/src/java.base/share/classes/java/util/regex/Pattern.java b/src/java.base/share/classes/java/util/regex/Pattern.java
--- a/src/java.base/share/classes/java/util/regex/Pattern.java
+++ b/src/java.base/share/classes/java/util/regex/Pattern.java
@@ -45,6 +45,8 @@
 
 import jdk.internal.util.ArraysSupport;
 
+import sun.security.action.GetPropertyAction;
+
 /**
  * A compiled representation of a regular expression.
  *
@@ -130,7 +132,9 @@
  * <tr><th style="vertical-align:top; font-weight:normal" id="escape">{@code \e}</th>
  *     <td headers="matches characters escape">The escape character (<code>'&#92;u001B'</code>)</td></tr>
  * <tr><th style="vertical-align:top; font-weight:normal" id="ctrl_x">{@code \c}<i>x</i></th>
- *     <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i></td></tr>
+ *     <td headers="matches characters ctrl_x">The control character corresponding to <i>x</i>
+ *         (<i>x</i> is either {@code A} through {@code Z} or one of
+ *          {@code ?}, {@code @}, {@code [}, {@code \\}, {@code ]}, {@code ^}, {@code _})</td></tr>
  *
  *  <tr><th colspan="2" style="padding-top:20px" id="classes">Character classes</th></tr>
  *
@@ -151,7 +155,7 @@
  *         except for {@code b} and {@code c}: {@code [ad-z]} (subtraction)</td></tr>
  * <tr><th style="vertical-align:top; font-weight:normal" id="subtraction2">{@code [a-z&&[^m-p]]}</th>
  *     <td headers="matches classes subtraction2">{@code a} through {@code z},
- *          and not {@code m} through {@code p}: {@code [a-lq-z]}(subtraction)</td></tr>
+ *          and not {@code m} through {@code p}: {@code [a-lq-z]} (subtraction)</td></tr>
  *
  * <tr><th colspan="2" style="padding-top:20px" id="predef">Predefined character classes</th></tr>
  *
@@ -1058,6 +1062,25 @@
     private transient boolean hasSupplementary;
 
     /**
+     * If {@code true} then only limited list of chars is accepted as
+     * control-character IDs in regular expressions of form "\\cX":
+     * 'A' through 'Z', '?', '@', '[', '\\', ']', '^', '_'.
+     * Otherwise, no restrictions on the IDs are exposed.
+     */
+    private static final boolean RESTRICTED_CONTROL_CHAR_IDS = Boolean.valueOf(
+            GetPropertyAction.privilegedGetProperty(
+                    "jdk.util.regex.restrictedControlCharIds", "true"));
+
+    /**
+     * If {@code true} then lower-case control-character ids are mapped to the
+     * their upper-case counterparts.
+     * For example, "\\ca" will be the same as "\\cA".
+     */
+    private static final boolean ALLOW_LOWERCASE_CONTROL_CHAR_IDS = Boolean.valueOf(
+            GetPropertyAction.privilegedGetProperty(
+                    "jdk.util.regex.allowLowerCaseControlCharIds", "false"));
+
+    /**
      * Compiles the given regular expression into a pattern.
      *
      * @param  regex
@@ -3325,7 +3348,11 @@
      */
     private int c() {
         if (cursor < patternLength) {
-            return read() ^ 64;
+            int ch = read();
+            if (ALLOW_LOWERCASE_CONTROL_CHAR_IDS && ASCII.isLower(ch))
+                return ch ^ 0x60;
+            if (!RESTRICTED_CONTROL_CHAR_IDS || ASCII.isCntrlId(ch))
+                return ch ^ 0x40;
         }
         throw error("Illegal control escape sequence");
     }
diff --git a/test/jdk/java/util/regex/RegExTest.java b/test/jdk/java/util/regex/RegExTest.java
--- a/test/jdk/java/util/regex/RegExTest.java
+++ b/test/jdk/java/util/regex/RegExTest.java
@@ -35,7 +35,7 @@
  * 8027645 8035076 8039124 8035975 8074678 6854417 8143854 8147531 7071819
  * 8151481 4867170 7080302 6728861 6995635 6736245 4916384 6328855 6192895
  * 6345469 6988218 6693451 7006761 8140212 8143282 8158482 8176029 8184706
- * 8194667 8197462 8184692 8221431 8224789 8228352
+ * 8194667 8197462 8184692 8221431 8224789 8228352 8230365
  *
  * @library /test/lib
  * @library /lib/testlibrary/java/lang
@@ -57,6 +57,7 @@
 import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Random;
 import java.util.Scanner;
@@ -186,6 +187,7 @@
         invalidGroupName();
         illegalRepetitionRange();
         surrogatePairWithCanonEq();
+        controlCharacters();
 
         if (failure) {
             throw new
@@ -4984,4 +4986,75 @@
         }
         report("surrogatePairWithCanonEq");
     }
+
+    private static void controlCharacters() {
+        char[] contolCharsPairs = { '@', 0x00,
+            'A', 0x01, 'B', 0x02, 'C', 0x03, 'D', 0x04, 'E', 0x05, 'F', 0x06,
+            'G', 0x07, 'H', 0x08, 'I', 0x09, 'J', 0x0a, 'K', 0x0b, 'L', 0x0c,
+            'M', 0x0d, 'N', 0x0e, 'O', 0x0f, 'P', 0x10, 'Q', 0x11, 'R', 0x12,
+            'S', 0x13, 'T', 0x14, 'U', 0x15, 'V', 0x16, 'W', 0x17, 'X', 0x18,
+            'Y', 0x19, 'Z', 0x1a,
+            '[', 0x1b, '\\', 0x1c, ']', 0x1d, '^', 0x1e, '_', 0x1f, '?', 0x7f };
+        var contolChars = new HashMap<Character, Integer>();
+        for (int i = 0; i < contolCharsPairs.length; i += 2)
+            contolChars.put(Character.valueOf(contolCharsPairs[i]),
+                            Integer.valueOf(contolCharsPairs[i + 1]));
+
+        for (char chP = 0; chP <= 0xff + 16; ++chP) {
+            String pat = "\\c";
+            if (chP < 0xff) {
+                // \cx with ASCII x
+                pat = "\\c" + Character.toString(chP);
+            } else if (chP == 0xff) {
+                // incomplete \c at the end of pattern
+                pat = "\\c";
+            } else if (chP <= 0xff + 8) {
+                // \cx with a random non-ASCII char x
+                int x = 0xff + generator.nextInt(0xff00 + 1);
+                pat = "\\c" + Character.toString(x);
+            } else {
+                // \cx with a random non-ASCII codepoint x
+                int x = 0xff + generator.nextInt(Character.MAX_CODE_POINT + 1 - 0xff);
+                pat = "\\c" + Character.toString(x);
+            }
+            if (contolChars.containsKey(chP)) {
+                try {
+                    Pattern p = Pattern.compile(pat);
+                    for (int chS = 0; chS < 0xff; ++chS) {
+                        Matcher m = p.matcher(Character.toString(chS));
+                        if (m.matches() && contolChars.get(chP) != chS) {
+                            failCount++;
+                            System.out.println("Control character 0x" + Integer.toHexString(chS) +
+                                               " unexpectedly matched pattern " + pat);
+                        } else if (!m.matches() && contolChars.get(chP) == chS) {
+                            failCount++;
+                            System.out.println("Control character 0x" + Integer.toHexString(chS) +
+                                               " failed to match pattern " + pat);
+                        }
+                        if (m.matches() && Character.getType(chS) != Character.CONTROL) {
+                            failCount++;
+                            System.out.println("Non-control character 0x" + Integer.toHexString(chS) +
+                                               " unexpectedly matched pattern " + pat);
+                        }
+                    }
+                } catch (Throwable t) {
+                    failCount++;
+                    System.out.println("Failed to compile pattern " + pat +
+                                       " due to exception: " + t);
+                }
+            } else {
+                try {
+                    Pattern p = Pattern.compile(pat);
+                    failCount++;
+                    System.out.println("Expected to throw an exception when compiling " + pat);
+                } catch (PatternSyntaxException expected) {
+                } catch (Throwable t) {
+                    failCount++;
+                    System.out.println("Unexpected exception when compiling " + pat +
+                                       " : " + t);
+                }
+            }
+        }
+        report("controlCharacters");
+    }
 }