Add m-esr52 at 52.6.0

1 files changed, 854 insertions, 0 deletions

diff --git a/parser/html/javasrc/MetaScanner.java b/parser/html/javasrc/MetaScanner.java
new file mode 100644
index 000000000..be9aabfe3
--- /dev/null
+++ b/parser/html/javasrc/MetaScanner.java
@@ -0,0 +1,854 @@
+/*
+ * Copyright (c) 2007 Henri Sivonen
+ * Copyright (c) 2008-2015 Mozilla Foundation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a 
+ * copy of this software and associated documentation files (the "Software"), 
+ * to deal in the Software without restriction, including without limitation 
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+ * and/or sell copies of the Software, and to permit persons to whom the 
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in 
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+package nu.validator.htmlparser.impl;
+
+import java.io.IOException;
+
+import nu.validator.htmlparser.annotation.Auto;
+import nu.validator.htmlparser.annotation.Inline;
+import nu.validator.htmlparser.common.ByteReadable;
+
+import org.xml.sax.SAXException;
+
+public abstract class MetaScanner {
+
+    /**
+     * Constant for "charset".
+     */
+    private static final char[] CHARSET = { 'h', 'a', 'r', 's', 'e', 't' };
+    
+    /**
+     * Constant for "content".
+     */
+    private static final char[] CONTENT = { 'o', 'n', 't', 'e', 'n', 't' };
+
+    /**
+     * Constant for "http-equiv".
+     */
+    private static final char[] HTTP_EQUIV = { 't', 't', 'p', '-', 'e', 'q',
+            'u', 'i', 'v' };
+
+    /**
+     * Constant for "content-type".
+     */
+    private static final char[] CONTENT_TYPE = { 'c', 'o', 'n', 't', 'e', 'n',
+            't', '-', 't', 'y', 'p', 'e' };
+
+    private static final int NO = 0;
+
+    private static final int M = 1;
+    
+    private static final int E = 2;
+    
+    private static final int T = 3;
+
+    private static final int A = 4;
+    
+    private static final int DATA = 0;
+
+    private static final int TAG_OPEN = 1;
+
+    private static final int SCAN_UNTIL_GT = 2;
+
+    private static final int TAG_NAME = 3;
+
+    private static final int BEFORE_ATTRIBUTE_NAME = 4;
+
+    private static final int ATTRIBUTE_NAME = 5;
+
+    private static final int AFTER_ATTRIBUTE_NAME = 6;
+
+    private static final int BEFORE_ATTRIBUTE_VALUE = 7;
+
+    private static final int ATTRIBUTE_VALUE_DOUBLE_QUOTED = 8;
+
+    private static final int ATTRIBUTE_VALUE_SINGLE_QUOTED = 9;
+
+    private static final int ATTRIBUTE_VALUE_UNQUOTED = 10;
+
+    private static final int AFTER_ATTRIBUTE_VALUE_QUOTED = 11;
+
+    private static final int MARKUP_DECLARATION_OPEN = 13;
+    
+    private static final int MARKUP_DECLARATION_HYPHEN = 14;
+
+    private static final int COMMENT_START = 15;
+
+    private static final int COMMENT_START_DASH = 16;
+
+    private static final int COMMENT = 17;
+
+    private static final int COMMENT_END_DASH = 18;
+
+    private static final int COMMENT_END = 19;
+    
+    private static final int SELF_CLOSING_START_TAG = 20;
+    
+    private static final int HTTP_EQUIV_NOT_SEEN = 0;
+    
+    private static final int HTTP_EQUIV_CONTENT_TYPE = 1;
+
+    private static final int HTTP_EQUIV_OTHER = 2;
+
+    /**
+     * The data source.
+     */
+    protected ByteReadable readable;
+    
+    /**
+     * The state of the state machine that recognizes the tag name "meta".
+     */
+    private int metaState = NO;
+
+    /**
+     * The current position in recognizing the attribute name "content".
+     */
+    private int contentIndex = Integer.MAX_VALUE;
+    
+    /**
+     * The current position in recognizing the attribute name "charset".
+     */
+    private int charsetIndex = Integer.MAX_VALUE;
+
+    /**
+     * The current position in recognizing the attribute name "http-equive".
+     */
+    private int httpEquivIndex = Integer.MAX_VALUE;
+
+    /**
+     * The current position in recognizing the attribute value "content-type".
+     */
+    private int contentTypeIndex = Integer.MAX_VALUE;
+
+    /**
+     * The tokenizer state.
+     */
+    protected int stateSave = DATA;
+
+    /**
+     * The currently filled length of strBuf.
+     */
+    private int strBufLen;
+
+    /**
+     * Accumulation buffer for attribute values.
+     */
+    private @Auto char[] strBuf;
+    
+    private String content;
+    
+    private String charset;
+    
+    private int httpEquivState;
+    
+    // CPPONLY: private TreeBuilder treeBuilder;
+
+    public MetaScanner(
+        // CPPONLY: TreeBuilder tb
+    ) {
+        this.readable = null;
+        this.metaState = NO;
+        this.contentIndex = Integer.MAX_VALUE;
+        this.charsetIndex = Integer.MAX_VALUE;
+        this.httpEquivIndex = Integer.MAX_VALUE;
+        this.contentTypeIndex = Integer.MAX_VALUE;
+        this.stateSave = DATA;
+        this.strBufLen = 0;
+        this.strBuf = new char[36];
+        this.content = null;
+        this.charset = null;
+        this.httpEquivState = HTTP_EQUIV_NOT_SEEN;
+        // CPPONLY: this.treeBuilder = tb;
+    }
+    
+    @SuppressWarnings("unused") private void destructor() {
+        Portability.releaseString(content);
+        Portability.releaseString(charset);
+    }
+
+    // [NOCPP[
+    
+    /**
+     * Reads a byte from the data source.
+     * 
+     * -1 means end.
+     * @return
+     * @throws IOException
+     */
+    protected int read() throws IOException {
+        return readable.readByte();
+    }
+
+    // ]NOCPP]
+
+    // WARNING When editing this, makes sure the bytecode length shown by javap
+    // stays under 8000 bytes!
+    /**
+     * The runs the meta scanning algorithm.
+     */
+    protected final void stateLoop(int state)
+            throws SAXException, IOException {
+        int c = -1;
+        boolean reconsume = false;
+        stateloop: for (;;) {
+            switch (state) {
+                case DATA:
+                    dataloop: for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '<':
+                                state = MetaScanner.TAG_OPEN;
+                                break dataloop; // FALL THROUGH continue
+                            // stateloop;
+                            default:
+                                continue;
+                        }
+                    }
+                    // WARNING FALLTHRU CASE TRANSITION: DON'T REORDER
+                case TAG_OPEN:
+                    tagopenloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case 'm':
+                            case 'M':
+                                metaState = M;
+                                state = MetaScanner.TAG_NAME;
+                                break tagopenloop;
+                                // continue stateloop;                                
+                            case '!':
+                                state = MetaScanner.MARKUP_DECLARATION_OPEN;
+                                continue stateloop;
+                            case '?':
+                            case '/':
+                                state = MetaScanner.SCAN_UNTIL_GT;
+                                continue stateloop;
+                            case '>':
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z')) {
+                                    metaState = NO;
+                                    state = MetaScanner.TAG_NAME;
+                                    break tagopenloop;
+                                    // continue stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                reconsume = true;
+                                continue stateloop;
+                        }
+                    }
+                    // FALL THROUGH DON'T REORDER
+                case TAG_NAME:
+                    tagnameloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                state = MetaScanner.BEFORE_ATTRIBUTE_NAME;
+                                break tagnameloop;
+                            // continue stateloop;
+                            case '/':
+                                state = MetaScanner.SELF_CLOSING_START_TAG;
+                                continue stateloop;
+                            case '>':
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            case 'e':
+                            case 'E':
+                                if (metaState == M) {
+                                    metaState = E;
+                                } else {
+                                    metaState = NO;
+                                }
+                                continue;
+                            case 't':
+                            case 'T':
+                                if (metaState == E) {
+                                    metaState = T;
+                                } else {
+                                    metaState = NO;
+                                }
+                                continue;
+                            case 'a':
+                            case 'A':
+                                if (metaState == T) {
+                                    metaState = A;
+                                } else {
+                                    metaState = NO;
+                                }
+                                continue;
+                            default:
+                                metaState = NO;
+                                continue;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case BEFORE_ATTRIBUTE_NAME:
+                    beforeattributenameloop: for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        /*
+                         * Consume the next input character:
+                         */
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                continue;
+                            case '/':
+                                state = MetaScanner.SELF_CLOSING_START_TAG;
+                                continue stateloop;
+                            case '>':
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = DATA;
+                                continue stateloop;
+                            case 'c':
+                            case 'C':
+                                contentIndex = 0;
+                                charsetIndex = 0;
+                                httpEquivIndex = Integer.MAX_VALUE;
+                                contentTypeIndex = Integer.MAX_VALUE;
+                                state = MetaScanner.ATTRIBUTE_NAME;
+                                break beforeattributenameloop;                                
+                            case 'h':
+                            case 'H':
+                                contentIndex = Integer.MAX_VALUE;
+                                charsetIndex = Integer.MAX_VALUE;
+                                httpEquivIndex = 0;
+                                contentTypeIndex = Integer.MAX_VALUE;
+                                state = MetaScanner.ATTRIBUTE_NAME;
+                                break beforeattributenameloop;                                
+                            default:
+                                contentIndex = Integer.MAX_VALUE;
+                                charsetIndex = Integer.MAX_VALUE;
+                                httpEquivIndex = Integer.MAX_VALUE;
+                                contentTypeIndex = Integer.MAX_VALUE;
+                                state = MetaScanner.ATTRIBUTE_NAME;
+                                break beforeattributenameloop;
+                            // continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case ATTRIBUTE_NAME:
+                    attributenameloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                state = MetaScanner.AFTER_ATTRIBUTE_NAME;
+                                continue stateloop;
+                            case '/':
+                                state = MetaScanner.SELF_CLOSING_START_TAG;
+                                continue stateloop;
+                            case '=':
+                                strBufLen = 0;
+                                contentTypeIndex = 0;
+                                state = MetaScanner.BEFORE_ATTRIBUTE_VALUE;
+                                break attributenameloop;
+                            // continue stateloop;
+                            case '>':
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                if (metaState == A) {
+                                    if (c >= 'A' && c <= 'Z') {
+                                        c += 0x20;
+                                    }
+                                    if (contentIndex < CONTENT.length && c == CONTENT[contentIndex]) {
+                                        ++contentIndex;
+                                    } else {
+                                        contentIndex = Integer.MAX_VALUE;
+                                    }
+                                    if (charsetIndex < CHARSET.length && c == CHARSET[charsetIndex]) {
+                                        ++charsetIndex;
+                                    } else {
+                                        charsetIndex = Integer.MAX_VALUE;
+                                    }
+                                    if (httpEquivIndex < HTTP_EQUIV.length && c == HTTP_EQUIV[httpEquivIndex]) {
+                                        ++httpEquivIndex;
+                                    } else {
+                                        httpEquivIndex = Integer.MAX_VALUE;
+                                    }                                    
+                                }
+                                continue;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case BEFORE_ATTRIBUTE_VALUE:
+                    beforeattributevalueloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                continue;
+                            case '"':
+                                state = MetaScanner.ATTRIBUTE_VALUE_DOUBLE_QUOTED;
+                                break beforeattributevalueloop;
+                            // continue stateloop;
+                            case '\'':
+                                state = MetaScanner.ATTRIBUTE_VALUE_SINGLE_QUOTED;
+                                continue stateloop;
+                            case '>':
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                handleCharInAttributeValue(c);
+                                state = MetaScanner.ATTRIBUTE_VALUE_UNQUOTED;
+                                continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case ATTRIBUTE_VALUE_DOUBLE_QUOTED:
+                    attributevaluedoublequotedloop: for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '"':
+                                handleAttributeValue();
+                                state = MetaScanner.AFTER_ATTRIBUTE_VALUE_QUOTED;
+                                break attributevaluedoublequotedloop;
+                            // continue stateloop;
+                            default:
+                                handleCharInAttributeValue(c);
+                                continue;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case AFTER_ATTRIBUTE_VALUE_QUOTED:
+                    afterattributevaluequotedloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                state = MetaScanner.BEFORE_ATTRIBUTE_NAME;
+                                continue stateloop;
+                            case '/':
+                                state = MetaScanner.SELF_CLOSING_START_TAG;
+                                break afterattributevaluequotedloop;
+                            // continue stateloop;
+                            case '>':
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                state = MetaScanner.BEFORE_ATTRIBUTE_NAME;
+                                reconsume = true;
+                                continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case SELF_CLOSING_START_TAG:
+                    c = read();
+                    switch (c) {
+                        case -1:
+                            break stateloop;
+                        case '>':
+                            if (handleTag()) {
+                                break stateloop;
+                            }
+                            state = MetaScanner.DATA;
+                            continue stateloop;
+                        default:
+                            state = MetaScanner.BEFORE_ATTRIBUTE_NAME;
+                            reconsume = true;
+                            continue stateloop;
+                    }
+                    // XXX reorder point
+                case ATTRIBUTE_VALUE_UNQUOTED:
+                    for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+
+                            case '\u000C':
+                                handleAttributeValue();
+                                state = MetaScanner.BEFORE_ATTRIBUTE_NAME;
+                                continue stateloop;
+                            case '>':
+                                handleAttributeValue();
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                handleCharInAttributeValue(c);
+                                continue;
+                        }
+                    }
+                    // XXX reorder point
+                case AFTER_ATTRIBUTE_NAME:
+                    for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case ' ':
+                            case '\t':
+                            case '\n':
+                            case '\u000C':
+                                continue;
+                            case '/':
+                                handleAttributeValue();
+                                state = MetaScanner.SELF_CLOSING_START_TAG;
+                                continue stateloop;
+                            case '=':
+                                strBufLen = 0;
+                                contentTypeIndex = 0;
+                                state = MetaScanner.BEFORE_ATTRIBUTE_VALUE;
+                                continue stateloop;
+                            case '>':
+                                handleAttributeValue();
+                                if (handleTag()) {
+                                    break stateloop;
+                                }
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            case 'c':
+                            case 'C':
+                                contentIndex = 0;
+                                charsetIndex = 0;
+                                state = MetaScanner.ATTRIBUTE_NAME;
+                                continue stateloop;
+                            default:
+                                contentIndex = Integer.MAX_VALUE;
+                                charsetIndex = Integer.MAX_VALUE;
+                                state = MetaScanner.ATTRIBUTE_NAME;
+                                continue stateloop;
+                        }
+                    }
+                    // XXX reorder point
+                case MARKUP_DECLARATION_OPEN:
+                    markupdeclarationopenloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '-':
+                                state = MetaScanner.MARKUP_DECLARATION_HYPHEN;
+                                break markupdeclarationopenloop;
+                            // continue stateloop;
+                            default:
+                                state = MetaScanner.SCAN_UNTIL_GT;
+                                reconsume = true;
+                                continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case MARKUP_DECLARATION_HYPHEN:
+                    markupdeclarationhyphenloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '-':
+                                state = MetaScanner.COMMENT_START;
+                                break markupdeclarationhyphenloop;
+                            // continue stateloop;
+                            default:
+                                state = MetaScanner.SCAN_UNTIL_GT;
+                                reconsume = true;
+                                continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case COMMENT_START:
+                    commentstartloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '-':
+                                state = MetaScanner.COMMENT_START_DASH;
+                                continue stateloop;
+                            case '>':
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                state = MetaScanner.COMMENT;
+                                break commentstartloop;
+                            // continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case COMMENT:
+                    commentloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '-':
+                                state = MetaScanner.COMMENT_END_DASH;
+                                break commentloop;
+                            // continue stateloop;
+                            default:
+                                continue;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case COMMENT_END_DASH:
+                    commentenddashloop: for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '-':
+                                state = MetaScanner.COMMENT_END;
+                                break commentenddashloop;
+                            // continue stateloop;
+                            default:
+                                state = MetaScanner.COMMENT;
+                                continue stateloop;
+                        }
+                    }
+                    // FALLTHRU DON'T REORDER
+                case COMMENT_END:
+                    for (;;) {
+                        c = read();
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '>':
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            case '-':
+                                continue;
+                            default:
+                                state = MetaScanner.COMMENT;
+                                continue stateloop;
+                        }
+                    }
+                    // XXX reorder point
+                case COMMENT_START_DASH:
+                    c = read();
+                    switch (c) {
+                        case -1:
+                            break stateloop;
+                        case '-':
+                            state = MetaScanner.COMMENT_END;
+                            continue stateloop;
+                        case '>':
+                            state = MetaScanner.DATA;
+                            continue stateloop;
+                        default:
+                            state = MetaScanner.COMMENT;
+                            continue stateloop;
+                    }
+                    // XXX reorder point
+                case ATTRIBUTE_VALUE_SINGLE_QUOTED:
+                    for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '\'':
+                                handleAttributeValue();
+                                state = MetaScanner.AFTER_ATTRIBUTE_VALUE_QUOTED;
+                                continue stateloop;
+                            default:
+                                handleCharInAttributeValue(c);
+                                continue;
+                        }
+                    }
+                    // XXX reorder point
+                case SCAN_UNTIL_GT:
+                    for (;;) {
+                        if (reconsume) {
+                            reconsume = false;
+                        } else {
+                            c = read();
+                        }
+                        switch (c) {
+                            case -1:
+                                break stateloop;
+                            case '>':
+                                state = MetaScanner.DATA;
+                                continue stateloop;
+                            default:
+                                continue;
+                        }
+                    }
+            }
+        }
+        stateSave  = state;
+    }
+
+    private void handleCharInAttributeValue(int c) {
+        if (metaState == A) {
+            if (contentIndex == CONTENT.length || charsetIndex == CHARSET.length) {
+                addToBuffer(c);
+            } else if (httpEquivIndex == HTTP_EQUIV.length) {
+                if (contentTypeIndex < CONTENT_TYPE.length && toAsciiLowerCase(c) == CONTENT_TYPE[contentTypeIndex]) {
+                    ++contentTypeIndex;
+                } else {
+                    contentTypeIndex = Integer.MAX_VALUE;
+                }
+            }
+        }
+    }
+
+    @Inline private int toAsciiLowerCase(int c) {
+        if (c >= 'A' && c <= 'Z') {
+            return c + 0x20;
+        }
+        return c;
+    }
+
+    /**
+     * Adds a character to the accumulation buffer.
+     * @param c the character to add
+     */
+    private void addToBuffer(int c) {
+        if (strBufLen == strBuf.length) {
+            char[] newBuf = new char[strBuf.length + (strBuf.length << 1)];
+            System.arraycopy(strBuf, 0, newBuf, 0, strBuf.length);
+            strBuf = newBuf;
+        }
+        strBuf[strBufLen++] = (char)c;
+    }
+
+    /**
+     * Attempts to extract a charset name from the accumulation buffer.
+     * @return <code>true</code> if successful
+     * @throws SAXException
+     */
+    private void handleAttributeValue() throws SAXException {
+        if (metaState != A) {
+            return;
+        }
+        if (contentIndex == CONTENT.length && content == null) {
+            content = Portability.newStringFromBuffer(strBuf, 0, strBufLen
+                 // CPPONLY: , treeBuilder
+            );
+            return;
+        }
+        if (charsetIndex == CHARSET.length && charset == null) {
+            charset = Portability.newStringFromBuffer(strBuf, 0, strBufLen
+                 // CPPONLY: , treeBuilder
+            );
+            return;
+        }
+        if (httpEquivIndex == HTTP_EQUIV.length
+                && httpEquivState == HTTP_EQUIV_NOT_SEEN) {
+            httpEquivState = (contentTypeIndex == CONTENT_TYPE.length) ? HTTP_EQUIV_CONTENT_TYPE
+                    : HTTP_EQUIV_OTHER;
+            return;
+        }
+    }
+
+    private boolean handleTag() throws SAXException {
+        boolean stop = handleTagInner();
+        Portability.releaseString(content);
+        content = null;
+        Portability.releaseString(charset);
+        charset = null;
+        httpEquivState = HTTP_EQUIV_NOT_SEEN;
+        return stop;
+    }
+    
+    private boolean handleTagInner() throws SAXException {
+        if (charset != null && tryCharset(charset)) {
+                return true;
+        }
+        if (content != null && httpEquivState == HTTP_EQUIV_CONTENT_TYPE) {
+            String extract = TreeBuilder.extractCharsetFromContent(content
+                // CPPONLY: , treeBuilder
+            );
+            if (extract == null) {
+                return false;
+            }
+            boolean success = tryCharset(extract);
+            Portability.releaseString(extract);
+            return success;
+        }
+        return false;
+    }
+
+    /**
+     * Tries to switch to an encoding.
+     * 
+     * @param encoding
+     * @return <code>true</code> if successful
+     * @throws SAXException
+     */
+    protected abstract boolean tryCharset(String encoding) throws SAXException;
+    
+}