Add an option to escape forward slash character

Squashed commit of the following:

commit 26d181059989279a79c433cedcd893b4f52e42ee
Author: Francois Chagnon <francois.chagnon@jadedpixel.com>
Date:   Tue Sep 15 21:17:34 2015 +0000

    add config options for escape_slash

commit fa282334051b16df91ca097dd7304b46f3bc7719
Author: Francois Chagnon <francois.chagnon@jadedpixel.com>
Date:   Mon Feb 9 21:09:33 2015 +0000

    add forward slash to escape character

9 files changed, 129 insertions, 17 deletions

diff --git a/ext/json/ext/generator/generator.c b/ext/json/ext/generator/generator.c
index 749efaf..80d1ca7 100644
--- a/ext/json/ext/generator/generator.c
+++ b/ext/json/ext/generator/generator.c
@@ -22,7 +22,7 @@ static ID i_to_s, i_to_json, i_new, i_indent, i_space, i_space_before,
           i_object_nl, i_array_nl, i_max_nesting, i_allow_nan, i_ascii_only,
           i_pack, i_unpack, i_create_id, i_extend, i_key_p,
           i_aref, i_send, i_respond_to_p, i_match, i_keys, i_depth,
-          i_buffer_initial_length, i_dup;
+          i_buffer_initial_length, i_dup, i_escape_slash;
 
 /*
  * Copyright 2001-2004 Unicode, Inc.
@@ -130,7 +130,7 @@ static void unicode_escape_to_buffer(FBuffer *buffer, char buf[6], UTF16
 
 /* Converts string to a JSON string in FBuffer buffer, where all but the ASCII
  * and control characters are JSON escaped. */
-static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string)
+static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string, char escape_slash)
 {
     const UTF8 *source = (UTF8 *) RSTRING_PTR(string);
     const UTF8 *sourceEnd = source + RSTRING_LEN(string);
@@ -180,6 +180,11 @@ static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string)
                         case '"':
                             fbuffer_append(buffer, "\\\"", 2);
                             break;
+                        case '/':
+                            if(escape_slash) {
+                                fbuffer_append(buffer, "\\/", 2);
+                                break;
+                            }
                         default:
                             fbuffer_append_char(buffer, (char)ch);
                             break;
@@ -229,7 +234,7 @@ static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string)
  * characters required by the JSON standard are JSON escaped. The remaining
  * characters (should be UTF8) are just passed through and appended to the
  * result. */
-static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string)
+static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string, char escape_slash)
 {
     const char *ptr = RSTRING_PTR(string), *p;
     unsigned long len = RSTRING_LEN(string), start = 0, end = 0;
@@ -280,6 +285,12 @@ static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string)
                     escape =  "\\\"";
                     escape_len = 2;
                     break;
+                case '/':
+                    if(escape_slash) {
+                        escape = "\\/";
+                        escape_len = 2;
+                        break;
+                    }
                 default:
                     {
                         unsigned short clen = 1;
@@ -716,6 +727,8 @@ static VALUE cState_configure(VALUE self, VALUE opts)
     state->allow_nan = RTEST(tmp);
     tmp = rb_hash_aref(opts, ID2SYM(i_ascii_only));
     state->ascii_only = RTEST(tmp);
+    tmp = rb_hash_aref(opts, ID2SYM(i_escape_slash));
+    state->escape_slash = RTEST(tmp);
     return self;
 }
 
@@ -750,6 +763,7 @@ static VALUE cState_to_h(VALUE self)
     rb_hash_aset(result, ID2SYM(i_allow_nan), state->allow_nan ? Qtrue : Qfalse);
     rb_hash_aset(result, ID2SYM(i_ascii_only), state->ascii_only ? Qtrue : Qfalse);
     rb_hash_aset(result, ID2SYM(i_max_nesting), LONG2FIX(state->max_nesting));
+    rb_hash_aset(result, ID2SYM(i_escape_slash), state->escape_slash ? Qtrue : Qfalse);
     rb_hash_aset(result, ID2SYM(i_depth), LONG2FIX(state->depth));
     rb_hash_aset(result, ID2SYM(i_buffer_initial_length), LONG2FIX(state->buffer_initial_length));
     return result;
@@ -934,9 +948,9 @@ static void generate_json_string(FBuffer *buffer, VALUE Vstate, JSON_Generator_S
     }
 #endif
     if (state->ascii_only) {
-        convert_UTF8_to_JSON_ASCII(buffer, obj);
+        convert_UTF8_to_JSON_ASCII(buffer, obj, state->escape_slash);
     } else {
-        convert_UTF8_to_JSON(buffer, obj);
+        convert_UTF8_to_JSON(buffer, obj, state->escape_slash);
     }
     fbuffer_append_char(buffer, '"');
 }
@@ -1378,6 +1392,31 @@ static VALUE cState_max_nesting_set(VALUE self, VALUE depth)
 }
 
 /*
+ * call-seq: escape_slash
+ *
+ * If this boolean is true, the forward slashes will be escaped in
+ * the json output.
+ */
+static VALUE cState_escape_slash(VALUE self)
+{
+    GET_STATE(self);
+    return state->escape_slash ? Qtrue : Qfalse;
+}
+
+/*
+ * call-seq: escape_slash=(depth)
+ *
+ * This sets whether or not the forward slashes will be escaped in
+ * the json output.
+ */
+static VALUE cState_escape_slash_set(VALUE self, VALUE enable)
+{
+    GET_STATE(self);
+    state->escape_slash = RTEST(enable);
+    return Qnil;
+}
+
+/*
  * call-seq: allow_nan?
  *
  * Returns true, if NaN, Infinity, and -Infinity should be generated, otherwise
@@ -1489,6 +1528,9 @@ void Init_generator(void)
     rb_define_method(cState, "array_nl=", cState_array_nl_set, 1);
     rb_define_method(cState, "max_nesting", cState_max_nesting, 0);
     rb_define_method(cState, "max_nesting=", cState_max_nesting_set, 1);
+    rb_define_method(cState, "escape_slash", cState_escape_slash, 0);
+    rb_define_method(cState, "escape_slash?", cState_escape_slash, 0);
+    rb_define_method(cState, "escape_slash=", cState_escape_slash_set, 1);
     rb_define_method(cState, "check_circular?", cState_check_circular_p, 0);
     rb_define_method(cState, "allow_nan?", cState_allow_nan_p, 0);
     rb_define_method(cState, "ascii_only?", cState_ascii_only_p, 0);
@@ -1545,6 +1587,7 @@ void Init_generator(void)
     i_object_nl = rb_intern("object_nl");
     i_array_nl = rb_intern("array_nl");
     i_max_nesting = rb_intern("max_nesting");
+    i_escape_slash = rb_intern("escape_slash");
     i_allow_nan = rb_intern("allow_nan");
     i_ascii_only = rb_intern("ascii_only");
     i_depth = rb_intern("depth");
diff --git a/ext/json/ext/generator/generator.h b/ext/json/ext/generator/generator.h
index c367a62..3ebd622 100644
--- a/ext/json/ext/generator/generator.h
+++ b/ext/json/ext/generator/generator.h
@@ -49,8 +49,8 @@ static const UTF32 halfMask = 0x3FFUL;
 static unsigned char isLegalUTF8(const UTF8 *source, unsigned long length);
 static void unicode_escape(char *buf, UTF16 character);
 static void unicode_escape_to_buffer(FBuffer *buffer, char buf[6], UTF16 character);
-static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string);
-static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string);
+static void convert_UTF8_to_JSON_ASCII(FBuffer *buffer, VALUE string, char escape_slash);
+static void convert_UTF8_to_JSON(FBuffer *buffer, VALUE string, char escape_slash);
 static char *fstrndup(const char *ptr, unsigned long len);
 
 /* ruby api and some helpers */
@@ -72,6 +72,7 @@ typedef struct JSON_Generator_StateStruct {
     long max_nesting;
     char allow_nan;
     char ascii_only;
+    char escape_slash;
     long depth;
     long buffer_initial_length;
 } JSON_Generator_State;
@@ -150,6 +151,8 @@ static VALUE cState_allow_nan_p(VALUE self);
 static VALUE cState_ascii_only_p(VALUE self);
 static VALUE cState_depth(VALUE self);
 static VALUE cState_depth_set(VALUE self, VALUE depth);
+static VALUE cState_escape_slash(VALUE self);
+static VALUE cState_escape_slash_set(VALUE self, VALUE depth);
 static FBuffer *cState_prepare_buffer(VALUE self);
 #ifndef ZALLOC
 #define ZALLOC(type) ((type *)ruby_zalloc(sizeof(type)))
diff --git a/java/src/json/ext/Generator.java b/java/src/json/ext/Generator.java
index 24bf049..cd23c73 100644
--- a/java/src/json/ext/Generator.java
+++ b/java/src/json/ext/Generator.java
@@ -158,7 +158,7 @@ public final class Generator {
 
         public StringEncoder getStringEncoder() {
             if (stringEncoder == null) {
-                stringEncoder = new StringEncoder(context, getState().asciiOnly());
+                stringEncoder = new StringEncoder(context, getState().asciiOnly(), getState().escapeSlash());
             }
             return stringEncoder;
         }
diff --git a/java/src/json/ext/GeneratorState.java b/java/src/json/ext/GeneratorState.java
index 44a9311..7fec09d 100644
--- a/java/src/json/ext/GeneratorState.java
+++ b/java/src/json/ext/GeneratorState.java
@@ -83,6 +83,12 @@ public class GeneratorState extends RubyObject {
     private boolean quirksMode = DEFAULT_QUIRKS_MODE;
     static final boolean DEFAULT_QUIRKS_MODE = false;
     /**
+     * If set to <code>true</code> the forward slash will be escaped in
+     * json output.
+     */
+    private boolean escapeSlash = DEFAULT_ESCAPE_SLASH;
+    static final boolean DEFAULT_ESCAPE_SLASH = false;
+    /**
      * The initial buffer length of this state. (This isn't really used on all
      * non-C implementations.)
      */
@@ -171,6 +177,9 @@ public class GeneratorState extends RubyObject {
      * <code>-Infinity</code> should be generated, otherwise an exception is
      * thrown if these values are encountered.
      * This options defaults to <code>false</code>.
+     * <dt><code>:escape_slash</code>
+     * <dd>set to <code>true</code> if the forward slashes should be escaped
+     * in the json output (default: <code>false</code>)
      */
     @JRubyMethod(optional=1, visibility=Visibility.PRIVATE)
     public IRubyObject initialize(ThreadContext context, IRubyObject[] args) {
@@ -194,6 +203,7 @@ public class GeneratorState extends RubyObject {
         this.allowNaN = orig.allowNaN;
         this.asciiOnly = orig.asciiOnly;
         this.quirksMode = orig.quirksMode;
+        this.escapeSlash = orig.escapeSlash;
         this.bufferInitialLength = orig.bufferInitialLength;
         this.depth = orig.depth;
         return this;
@@ -346,6 +356,24 @@ public class GeneratorState extends RubyObject {
         return max_nesting;
     }
 
+    /**
+     * Returns true if forward slashes are escaped in the json output.
+     */
+    public boolean escapeSlash() {
+        return escapeSlash;
+    }
+
+    @JRubyMethod(name="escape_slash")
+    public RubyBoolean escape_slash_get(ThreadContext context) {
+        return context.getRuntime().newBoolean(escapeSlash);
+    }
+
+    @JRubyMethod(name="escape_slash=")
+    public IRubyObject escape_slash_set(IRubyObject escape_slash) {
+        escapeSlash = escape_slash.isTrue();
+        return escape_slash.getRuntime().newBoolean(escapeSlash);
+    }
+
     public boolean allowNaN() {
         return allowNaN;
     }
@@ -430,6 +458,7 @@ public class GeneratorState extends RubyObject {
         maxNesting = opts.getInt("max_nesting", DEFAULT_MAX_NESTING);
         allowNaN   = opts.getBool("allow_nan",  DEFAULT_ALLOW_NAN);
         asciiOnly  = opts.getBool("ascii_only", DEFAULT_ASCII_ONLY);
+        escapeSlash = opts.getBool("escape_slash", DEFAULT_ESCAPE_SLASH);
         bufferInitialLength = opts.getInt("buffer_initial_length", DEFAULT_BUFFER_INITIAL_LENGTH);
 
         depth = opts.getInt("depth", 0);
@@ -457,6 +486,7 @@ public class GeneratorState extends RubyObject {
         result.op_aset(context, runtime.newSymbol("allow_nan"), allow_nan_p(context));
         result.op_aset(context, runtime.newSymbol("ascii_only"), ascii_only_p(context));
         result.op_aset(context, runtime.newSymbol("max_nesting"), max_nesting_get(context));
+        result.op_aset(context, runtime.newSymbol("escape_slash"), escape_slash_get(context));
         result.op_aset(context, runtime.newSymbol("depth"), depth_get(context));
         result.op_aset(context, runtime.newSymbol("buffer_initial_length"), buffer_initial_length_get(context));
         for (String name: getInstanceVariableNameList()) {
diff --git a/java/src/json/ext/StringEncoder.java b/java/src/json/ext/StringEncoder.java
index 9d40dd3..26678ed 100644
--- a/java/src/json/ext/StringEncoder.java
+++ b/java/src/json/ext/StringEncoder.java
@@ -15,7 +15,7 @@ import org.jruby.util.ByteList;
  * and throws a GeneratorError if any problem is found.
  */
 final class StringEncoder extends ByteListTranscoder {
-    private final boolean asciiOnly;
+    private final boolean asciiOnly, escapeSlash;
 
     // Escaped characters will reuse this array, to avoid new allocations
     // or appending them byte-by-byte
@@ -37,9 +37,10 @@ final class StringEncoder extends ByteListTranscoder {
             new byte[] {'0', '1', '2', '3', '4', '5', '6', '7',
                         '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
 
-    StringEncoder(ThreadContext context, boolean asciiOnly) {
+    StringEncoder(ThreadContext context, boolean asciiOnly, boolean escapeSlash) {
         super(context);
         this.asciiOnly = asciiOnly;
+        this.escapeSlash = escapeSlash;
     }
 
     void encode(ByteList src, ByteList out) {
@@ -73,6 +74,11 @@ final class StringEncoder extends ByteListTranscoder {
         case '\b':
             escapeChar('b');
             break;
+        case '/':
+            if(escapeSlash) {
+                escapeChar((char)c);
+                break;
+            }
         default:
             if (c >= 0x20 && c <= 0x7f ||
                     (c >= 0x80 && !asciiOnly)) {
diff --git a/lib/json/common.rb b/lib/json/common.rb
index 132e9c8..ed4e047 100644
--- a/lib/json/common.rb
+++ b/lib/json/common.rb
@@ -436,12 +436,13 @@ module JSON
     # Sets or returns the default options for the JSON.dump method.
     # Initially:
     #   opts = JSON.dump_default_options
-    #   opts # => {:max_nesting=>false, :allow_nan=>true}
+    #   opts # => {:max_nesting=>false, :allow_nan=>true, :escape_slash=>false}
     attr_accessor :dump_default_options
   end
   self.dump_default_options = {
     :max_nesting => false,
     :allow_nan   => true,
+    :escape_slash => false,
   }
 
   # Dumps _obj_ as a JSON string, i.e. calls generate on the object and returns
diff --git a/lib/json/pure/generator.rb b/lib/json/pure/generator.rb
index 471af63..ef1c2e8 100644
--- a/lib/json/pure/generator.rb
+++ b/lib/json/pure/generator.rb
@@ -37,20 +37,26 @@ module JSON
     '\\'  =>  '\\\\',
   } # :nodoc:
 
+  ESCAPE_SLASH_MAP = MAP.merge(
+    '/'  =>  '\\/',
+  )
+
   # Convert a UTF8 encoded Ruby string _string_ to a JSON string, encoded with
   # UTF16 big endian characters as \u????, and return it.
-  def utf8_to_json(string) # :nodoc:
+  def utf8_to_json(string, escape_slash = false) # :nodoc:
     string = string.dup
     string.force_encoding(::Encoding::ASCII_8BIT)
-    string.gsub!(/["\\\x0-\x1f]/) { MAP[$&] }
+    map = escape_slash ? ESCAPE_SLASH_MAP : MAP
+    string.gsub!(/[\/"\\\x0-\x1f]/) { map[$&] || $& }
     string.force_encoding(::Encoding::UTF_8)
     string
   end
 
-  def utf8_to_json_ascii(string) # :nodoc:
+  def utf8_to_json_ascii(string, escape_slash = false) # :nodoc:
     string = string.dup
     string.force_encoding(::Encoding::ASCII_8BIT)
-    string.gsub!(/["\\\x0-\x1f]/n) { MAP[$&] }
+    map = escape_slash ? ESCAPE_SLASH_MAP : MAP
+    string.gsub!(/[\/"\\\x0-\x1f]/n) { map[$&] || $& }
     string.gsub!(/(
       (?:
        [\xc2-\xdf][\x80-\xbf]    |
@@ -109,6 +115,7 @@ module JSON
         # * *space_before*: a string that is put before a : pair delimiter (default: ''),
         # * *object_nl*: a string that is put at the end of a JSON object (default: ''),
         # * *array_nl*: a string that is put at the end of a JSON array (default: ''),
+        # * *escape_slash*: true if forward slash (/) should be escaped (default: false)
         # * *check_circular*: is deprecated now, use the :max_nesting option instead,
         # * *max_nesting*: sets the maximum level of data structure nesting in
         #   the generated JSON, max_nesting = 0 if no maximum should be checked.
@@ -123,6 +130,7 @@ module JSON
           @array_nl              = ''
           @allow_nan             = false
           @ascii_only            = false
+          @escape_slash          = false
           @buffer_initial_length = 1024
           configure opts
         end
@@ -148,6 +156,10 @@ module JSON
         # the generated JSON, max_nesting = 0 if no maximum is checked.
         attr_accessor :max_nesting
 
+        # If this attribute is set to true, forward slashes will be escaped in
+        # all json strings.
+        attr_accessor :escape_slash
+
         # :stopdoc:
         attr_reader :buffer_initial_length
 
@@ -187,6 +199,11 @@ module JSON
           @ascii_only
         end
 
+        # Returns true, if forward slashes are escaped. Otherwise returns false.
+        def escape_slash?
+          @escape_slash
+        end
+
         # Configure this State instance with the Hash _opts_, and return
         # itself.
         def configure(opts)
@@ -209,6 +226,7 @@ module JSON
           @ascii_only            = opts[:ascii_only] if opts.key?(:ascii_only)
           @depth                 = opts[:depth] || 0
           @buffer_initial_length ||= opts[:buffer_initial_length]
+          @escape_slash          = !!opts[:escape_slash] if opts.key?(:escape_slash)
 
           if !opts.key?(:max_nesting) # defaults to 100
             @max_nesting = 100
@@ -399,9 +417,9 @@ module JSON
               string = encode(::Encoding::UTF_8)
             end
             if state.ascii_only?
-              '"' << JSON.utf8_to_json_ascii(string) << '"'
+              '"' << JSON.utf8_to_json_ascii(string, state.escape_slash) << '"'
             else
-              '"' << JSON.utf8_to_json(string) << '"'
+              '"' << JSON.utf8_to_json(string, state.escape_slash) << '"'
             end
           end
 
diff --git a/tests/json_generator_test.rb b/tests/json_generator_test.rb
index ee19fa5..13d3b5a 100644..100755
--- a/tests/json_generator_test.rb
+++ b/tests/json_generator_test.rb
@@ -174,6 +174,7 @@ EOT
       :ascii_only            => false,
       :buffer_initial_length => 1024,
       :depth                 => 0,
+      :escape_slash          => false,
       :indent                => "  ",
       :max_nesting           => 100,
       :object_nl             => "\n",
@@ -190,6 +191,7 @@ EOT
       :ascii_only            => false,
       :buffer_initial_length => 1024,
       :depth                 => 0,
+      :escape_slash          => false,
       :indent                => "",
       :max_nesting           => 100,
       :object_nl             => "",
@@ -206,6 +208,7 @@ EOT
       :ascii_only            => false,
       :buffer_initial_length => 1024,
       :depth                 => 0,
+      :escape_slash          => false,
       :indent                => "",
       :max_nesting           => 0,
       :object_nl             => "",
@@ -394,6 +397,10 @@ EOT
     json = '["/"]'
     assert_equal json, generate(data)
     #
+    data = [ '/' ]
+    json = '["\/"]'
+    assert_equal json, generate(data, :escape_slash => true)
+    #
     data = ['"']
     json = '["\""]'
     assert_equal json, generate(data)
diff --git a/tests/json_parser_test.rb b/tests/json_parser_test.rb
index 9946dd9..514441e 100644
--- a/tests/json_parser_test.rb
+++ b/tests/json_parser_test.rb
@@ -293,6 +293,10 @@ EOT
     json = '["\\\'"]'
     data = ["'"]
     assert_equal data, parse(json)
+
+    json = '["\/"]'
+    data = [ '/' ]
+    assert_equal data, parse(json)
   end
 
   class SubArray < Array