Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 759 insertions, 0 deletions

diff --git a/sal/rtl/uri.cxx b/sal/rtl/uri.cxx
new file mode 100644
index 000000000..341455261
--- /dev/null
+++ b/sal/rtl/uri.cxx
@@ -0,0 +1,759 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <rtl/character.hxx>
+#include <rtl/strbuf.hxx>
+#include <rtl/textenc.h>
+#include <rtl/textcvt.h>
+#include <rtl/uri.h>
+#include <rtl/uri.hxx>
+#include <rtl/ustrbuf.h>
+#include <rtl/ustrbuf.hxx>
+#include <rtl/ustring.h>
+#include <rtl/ustring.hxx>
+#include <sal/types.h>
+#include <sal/macros.h>
+
+#include <uri_internal.hxx>
+
+#include <algorithm>
+#include <cstddef>
+
+namespace {
+
+sal_Unicode const cEscapePrefix = 0x25; // '%'
+
+int getHexWeight(sal_uInt32 nUtf32)
+{
+    return nUtf32 >= 0x30 && nUtf32 <= 0x39 ? // '0'--'9'
+               static_cast< int >(nUtf32 - 0x30) :
+           nUtf32 >= 0x41 && nUtf32 <= 0x46 ? // 'A'--'F'
+               static_cast< int >(nUtf32 - 0x41 + 10) :
+           nUtf32 >= 0x61 && nUtf32 <= 0x66 ? // 'a'--'f'
+               static_cast< int >(nUtf32 - 0x61 + 10) :
+               -1; // not a hex digit
+}
+
+bool isValid(sal_Bool const * pCharClass, sal_uInt32 nUtf32)
+{
+    return nUtf32 < rtl::UriCharClassSize && pCharClass[nUtf32];
+}
+
+void writeUnicode(rtl_uString ** pBuffer, sal_Int32 * pCapacity,
+                         sal_Unicode cChar)
+{
+    rtl_uStringbuffer_insert(pBuffer, pCapacity, (*pBuffer)->length, &cChar, 1);
+}
+
+}
+
+namespace rtl::uri::detail {
+
+/** Read any of the following:
+
+   @li sequence of escape sequences representing character from eCharset,
+       translated to single UCS4 character; or
+   @li pair of UTF-16 surrogates, translated to single UCS4 character; or
+   @li  single UTF-16 character, extended to UCS4 character.
+ */
+sal_uInt32 readUcs4(sal_Unicode const ** pBegin, sal_Unicode const * pEnd,
+                    bool bEncoded, rtl_TextEncoding eCharset,
+                    EscapeType * pType)
+{
+    sal_uInt32 nChar = *(*pBegin)++;
+    int nWeight1;
+    int nWeight2;
+    if (nChar == cEscapePrefix && bEncoded && pEnd - *pBegin >= 2
+        && (nWeight1 = getHexWeight((*pBegin)[0])) >= 0
+        && (nWeight2 = getHexWeight((*pBegin)[1])) >= 0)
+    {
+        *pBegin += 2;
+        nChar = static_cast< sal_uInt32 >(nWeight1 << 4 | nWeight2);
+        if (nChar <= 0x7F)
+        {
+            *pType = EscapeChar;
+        }
+        else if (eCharset == RTL_TEXTENCODING_UTF8)
+        {
+            if (nChar >= 0xC0 && nChar <= 0xF4)
+            {
+                sal_uInt32 nEncoded;
+                int nShift;
+                sal_uInt32 nMin;
+                if (nChar <= 0xDF)
+                {
+                    nEncoded = (nChar & 0x1F) << 6;
+                    nShift = 0;
+                    nMin = 0x80;
+                }
+                else if (nChar <= 0xEF)
+                {
+                    nEncoded = (nChar & 0x0F) << 12;
+                    nShift = 6;
+                    nMin = 0x800;
+                }
+                else
+                {
+                    nEncoded = (nChar & 0x07) << 18;
+                    nShift = 12;
+                    nMin = 0x10000;
+                }
+
+                sal_Unicode const * p = *pBegin;
+                bool bUTF8 = true;
+
+                for (; nShift >= 0; nShift -= 6)
+                {
+                    if (pEnd - p < 3 || p[0] != cEscapePrefix
+                        || (nWeight1 = getHexWeight(p[1])) < 8
+                        || nWeight1 > 11
+                        || (nWeight2 = getHexWeight(p[2])) < 0)
+                    {
+                        bUTF8 = false;
+                        break;
+                    }
+                    p += 3;
+                    nEncoded |= ((nWeight1 & 3) << 4 | nWeight2) << nShift;
+                }
+                if (bUTF8 && rtl::isUnicodeScalarValue(nEncoded)
+                    && nEncoded >= nMin)
+                {
+                    *pBegin = p;
+                    *pType = EscapeChar;
+                    return nEncoded;
+                }
+            }
+            *pType = EscapeOctet;
+        }
+        else
+        {
+            OStringBuffer aBuf;
+            aBuf.append(static_cast< char >(nChar));
+            rtl_TextToUnicodeConverter aConverter
+                = rtl_createTextToUnicodeConverter(eCharset);
+            sal_Unicode const * p = *pBegin;
+
+            for (;;)
+            {
+                sal_Unicode aDst[2];
+                sal_uInt32 nInfo;
+                sal_Size nConverted;
+                sal_Size nDstSize = rtl_convertTextToUnicode(
+                    aConverter, nullptr, aBuf.getStr(), aBuf.getLength(), aDst,
+                    SAL_N_ELEMENTS( aDst ),
+                    (RTL_TEXTTOUNICODE_FLAGS_UNDEFINED_ERROR
+                     | RTL_TEXTTOUNICODE_FLAGS_MBUNDEFINED_ERROR
+                     | RTL_TEXTTOUNICODE_FLAGS_INVALID_ERROR),
+                    &nInfo, &nConverted);
+
+                if (nInfo == 0)
+                {
+                    assert( nConverted
+                        == sal::static_int_cast< sal_uInt32 >(
+                            aBuf.getLength()));
+
+                    rtl_destroyTextToUnicodeConverter(aConverter);
+                    *pBegin = p;
+                    *pType = EscapeChar;
+
+                    assert( nDstSize == 1
+                        || (nDstSize == 2 && rtl::isHighSurrogate(aDst[0])
+                            && rtl::isLowSurrogate(aDst[1])));
+
+                    return nDstSize == 1
+                        ? aDst[0] : rtl::combineSurrogates(aDst[0], aDst[1]);
+                }
+                if (nInfo == RTL_TEXTTOUNICODE_INFO_SRCBUFFERTOOSMALL
+                         && pEnd - p >= 3 && p[0] == cEscapePrefix
+                         && (nWeight1 = getHexWeight(p[1])) >= 0
+                         && (nWeight2 = getHexWeight(p[2])) >= 0)
+                {
+                    p += 3;
+                    aBuf.append(static_cast< char >(nWeight1 << 4 | nWeight2));
+                }
+                else if (nInfo == RTL_TEXTTOUNICODE_INFO_SRCBUFFERTOOSMALL
+                         && p != pEnd && *p <= 0x7F)
+                {
+                    aBuf.append(static_cast< char >(*p++));
+                }
+                else
+                {
+                    assert(
+                        (nInfo & RTL_TEXTTOUNICODE_INFO_DESTBUFFERTOOSMALL)
+                        == 0);
+                    break;
+                }
+            }
+            rtl_destroyTextToUnicodeConverter(aConverter);
+            *pType = EscapeOctet;
+        }
+        return nChar;
+    }
+
+    *pType = EscapeNo;
+    return rtl::isHighSurrogate(nChar) && *pBegin < pEnd
+           && rtl::isLowSurrogate(**pBegin) ?
+               rtl::combineSurrogates(nChar, *(*pBegin)++) : nChar;
+}
+
+}
+
+namespace {
+
+void writeUcs4(rtl_uString ** pBuffer, sal_Int32 * pCapacity, sal_uInt32 nUtf32)
+{
+    rtl_uStringbuffer_insertUtf32(pBuffer, pCapacity, (*pBuffer)->length, nUtf32);
+}
+
+void writeEscapeOctet(rtl_uString ** pBuffer, sal_Int32 * pCapacity,
+                      sal_uInt32 nOctet)
+{
+    assert(nOctet <= 0xFF); // bad octet
+
+    static sal_Unicode const aHex[16]
+        = { 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+            0x41, 0x42, 0x43, 0x44, 0x45, 0x46 }; /* '0'--'9', 'A'--'F' */
+
+    writeUnicode(pBuffer, pCapacity, cEscapePrefix);
+    writeUnicode(pBuffer, pCapacity, aHex[nOctet >> 4]);
+    writeUnicode(pBuffer, pCapacity, aHex[nOctet & 15]);
+}
+
+bool writeEscapeChar(rtl_uString ** pBuffer, sal_Int32 * pCapacity,
+                     sal_uInt32 nUtf32, rtl_TextEncoding eCharset, bool bStrict)
+{
+    assert(rtl::isUnicodeCodePoint(nUtf32));
+    if (eCharset == RTL_TEXTENCODING_UTF8)
+    {
+        if (nUtf32 < 0x80)
+        {
+            writeEscapeOctet(pBuffer, pCapacity, nUtf32);
+        }
+        else if (nUtf32 < 0x800)
+        {
+            writeEscapeOctet(pBuffer, pCapacity, nUtf32 >> 6 | 0xC0);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 & 0x3F) | 0x80);
+        }
+        else if (nUtf32 < 0x10000)
+        {
+            writeEscapeOctet(pBuffer, pCapacity, nUtf32 >> 12 | 0xE0);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 >> 6 & 0x3F) | 0x80);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 & 0x3F) | 0x80);
+        }
+        else
+        {
+            writeEscapeOctet(pBuffer, pCapacity, nUtf32 >> 18 | 0xF0);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 >> 12 & 0x3F) | 0x80);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 >> 6 & 0x3F) | 0x80);
+            writeEscapeOctet(pBuffer, pCapacity, (nUtf32 & 0x3F) | 0x80);
+        }
+    }
+    else
+    {
+        rtl_UnicodeToTextConverter aConverter
+            = rtl_createUnicodeToTextConverter(eCharset);
+        sal_Unicode aSrc[2];
+        sal_Size nSrcSize = rtl::splitSurrogates(nUtf32, aSrc);
+
+        char aDst[32]; // FIXME  random value
+        sal_uInt32 nInfo;
+        sal_Size nConverted;
+        sal_Size nDstSize = rtl_convertUnicodeToText(
+            aConverter, nullptr, aSrc, nSrcSize, aDst, sizeof aDst,
+            RTL_UNICODETOTEXT_FLAGS_UNDEFINED_ERROR
+            | RTL_UNICODETOTEXT_FLAGS_INVALID_ERROR
+            | RTL_UNICODETOTEXT_FLAGS_FLUSH,
+            &nInfo, &nConverted);
+        assert((nInfo & RTL_UNICODETOTEXT_INFO_DESTBUFFERTOSMALL) == 0);
+        rtl_destroyUnicodeToTextConverter(aConverter);
+
+        if (nInfo == 0)
+        {
+            assert(nConverted == nSrcSize); // bad rtl_convertUnicodeToText
+
+            for (sal_Size i = 0; i < nDstSize; ++i)
+            {
+                writeEscapeOctet(pBuffer, pCapacity,
+                                 static_cast< unsigned char >(aDst[i]));
+                    // FIXME  all octets are escaped, even if there is no need
+            }
+        }
+        else
+        {
+            if (bStrict)
+                return false;
+
+            writeUcs4(pBuffer, pCapacity, nUtf32);
+        }
+    }
+    return true;
+}
+
+struct Component
+{
+    sal_Unicode const * pBegin;
+    sal_Unicode const * pEnd;
+
+    Component(): pBegin(nullptr), pEnd(nullptr) {}
+
+    bool isPresent() const { return pBegin != nullptr; }
+
+    sal_Int32 getLength() const;
+};
+
+sal_Int32 Component::getLength() const
+{
+    assert(isPresent()); // taking length of non-present component
+    return static_cast< sal_Int32 >(pEnd - pBegin);
+}
+
+struct Components
+{
+    Component aScheme;
+    Component aAuthority;
+    Component aPath;
+    Component aQuery;
+    Component aFragment;
+};
+
+void parseUriRef(rtl_uString const * pUriRef, Components * pComponents)
+{
+    // This algorithm is liberal and accepts various forms of illegal input.
+
+    sal_Unicode const * pBegin = pUriRef->buffer;
+    sal_Unicode const * pEnd = pBegin + pUriRef->length;
+    sal_Unicode const * pPos = pBegin;
+
+    if (pPos != pEnd && rtl::isAsciiAlpha(*pPos))
+    {
+        for (sal_Unicode const * p = pPos + 1; p != pEnd; ++p)
+        {
+            if (*p == ':')
+            {
+                pComponents->aScheme.pBegin = pBegin;
+                pComponents->aScheme.pEnd = ++p;
+                pPos = p;
+                break;
+            }
+
+            if (!rtl::isAsciiAlphanumeric(*p) && *p != '+' && *p != '-'
+                     && *p != '.')
+            {
+                break;
+            }
+        }
+    }
+
+    if (pEnd - pPos >= 2 && pPos[0] == '/' && pPos[1] == '/')
+    {
+        pComponents->aAuthority.pBegin = pPos;
+        pPos += 2;
+        while (pPos != pEnd && *pPos != '/' && *pPos != '?' && *pPos != '#')
+        {
+            ++pPos;
+        }
+
+        pComponents->aAuthority.pEnd = pPos;
+    }
+
+    pComponents->aPath.pBegin = pPos;
+    while (pPos != pEnd && *pPos != '?' && * pPos != '#')
+    {
+        ++pPos;
+    }
+
+    pComponents->aPath.pEnd = pPos;
+
+    if (pPos != pEnd && *pPos == '?')
+    {
+        pComponents->aQuery.pBegin = pPos++;
+        while (pPos != pEnd && * pPos != '#')
+        {
+            ++pPos;
+        }
+
+        pComponents->aQuery.pEnd = pPos;
+    }
+
+    if (pPos != pEnd)
+    {
+        assert(*pPos == '#');
+        pComponents->aFragment.pBegin = pPos;
+        pComponents->aFragment.pEnd = pEnd;
+    }
+}
+
+void appendPath(
+    OUStringBuffer & buffer, sal_Int32 bufferStart, bool precedingSlash,
+    sal_Unicode const * pathBegin, sal_Unicode const * pathEnd)
+{
+    while (precedingSlash || pathBegin != pathEnd)
+    {
+        sal_Unicode const * p = pathBegin;
+        while (p != pathEnd && *p != '/')
+        {
+            ++p;
+        }
+
+        std::size_t n = p - pathBegin;
+        if (n == 1 && pathBegin[0] == '.')
+        {
+            // input begins with "." -> remove from input (and done):
+            //  i.e., !precedingSlash -> !precedingSlash
+            // input begins with "./" -> remove from input:
+            //  i.e., !precedingSlash -> !precedingSlash
+            // input begins with "/." -> replace with "/" in input (and not yet
+            // done):
+            //  i.e., precedingSlash -> precedingSlash
+            // input begins with "/./" -> replace with "/" in input:
+            //  i.e., precedingSlash -> precedingSlash
+        }
+        else if (n == 2 && pathBegin[0] == '.' && pathBegin[1] == '.')
+        {
+            // input begins with ".." -> remove from input (and done):
+            //  i.e., !precedingSlash -> !precedingSlash
+            // input begins with "../" -> remove from input
+            //  i.e., !precedingSlash -> !precedingSlash
+            // input begins with "/.." -> replace with "/" in input, and shrink
+            // output (not yet done):
+            //  i.e., precedingSlash -> precedingSlash
+            // input begins with "/../" -> replace with "/" in input, and shrink
+            // output:
+            //  i.e., precedingSlash -> precedingSlash
+            if (precedingSlash)
+            {
+                buffer.truncate(
+                    bufferStart
+                    + std::max<sal_Int32>(
+                        rtl_ustr_lastIndexOfChar_WithLength(
+                            buffer.getStr() + bufferStart,
+                            buffer.getLength() - bufferStart, '/'),
+                        0));
+            }
+        }
+        else
+        {
+            if (precedingSlash)
+                buffer.append('/');
+
+            buffer.append(pathBegin, n);
+            precedingSlash = p != pathEnd;
+        }
+        pathBegin = p + (p == pathEnd ? 0 : 1);
+    }
+}
+
+}
+
+sal_Bool const * SAL_CALL rtl_getUriCharClass(rtl_UriCharClass eCharClass)
+    SAL_THROW_EXTERN_C()
+{
+    static constexpr std::array<sal_Bool, rtl::UriCharClassSize> aCharClass[] = {
+        rtl::createUriCharClass(u8""), // None
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-./:;=?@[]_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // Uric
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-.:;=?@_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // UricNoSlash
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-.;=@_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // RelSegment
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-.:;=@_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // RegName
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-.:;=_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // Userinfo
+        rtl::createUriCharClass(
+            u8"!$&'()*+,-.:=@_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"), // Pchar
+        rtl::createUriCharClass(
+            u8"!$&'()*+-./:?@_~"
+            "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")}; // UnoParamValue
+
+    assert(
+        (eCharClass >= 0
+         && (sal::static_int_cast< std::size_t >(eCharClass)
+             < SAL_N_ELEMENTS(aCharClass)))); // bad eCharClass
+    return aCharClass[eCharClass].data();
+}
+
+void SAL_CALL rtl_uriEncode(rtl_uString * pText, sal_Bool const * pCharClass,
+                            rtl_UriEncodeMechanism eMechanism,
+                            rtl_TextEncoding eCharset, rtl_uString ** pResult)
+    SAL_THROW_EXTERN_C()
+{
+    assert(!pCharClass[0x25]); // make sure the percent sign is encoded...
+
+    sal_Unicode const * p = pText->buffer;
+    sal_Unicode const * pEnd = p + pText->length;
+    sal_Int32 nCapacity = 256;
+    rtl_uString_new_WithLength(pResult, nCapacity);
+
+    while (p < pEnd)
+    {
+        rtl::uri::detail::EscapeType eType;
+        sal_uInt32 nUtf32 = rtl::uri::detail::readUcs4(
+            &p, pEnd,
+            (eMechanism == rtl_UriEncodeKeepEscapes
+             || eMechanism == rtl_UriEncodeCheckEscapes
+             || eMechanism == rtl_UriEncodeStrictKeepEscapes),
+            eCharset, &eType);
+
+        switch (eType)
+        {
+        case rtl::uri::detail::EscapeNo:
+            if (isValid(pCharClass, nUtf32)) // implies nUtf32 <= 0x7F
+            {
+                writeUnicode(pResult, &nCapacity,
+                             static_cast< sal_Unicode >(nUtf32));
+            }
+            else if (!writeEscapeChar(
+                         pResult, &nCapacity, nUtf32, eCharset,
+                         (eMechanism == rtl_UriEncodeStrict
+                          || eMechanism == rtl_UriEncodeStrictKeepEscapes)))
+            {
+                rtl_uString_new(pResult);
+                return;
+            }
+            break;
+
+        case rtl::uri::detail::EscapeChar:
+            if (eMechanism == rtl_UriEncodeCheckEscapes
+                && isValid(pCharClass, nUtf32)) // implies nUtf32 <= 0x7F
+            {
+                writeUnicode(pResult, &nCapacity,
+                             static_cast< sal_Unicode >(nUtf32));
+            }
+            else if (!writeEscapeChar(
+                         pResult, &nCapacity, nUtf32, eCharset,
+                         (eMechanism == rtl_UriEncodeStrict
+                          || eMechanism == rtl_UriEncodeStrictKeepEscapes)))
+            {
+                rtl_uString_new(pResult);
+                return;
+            }
+            break;
+
+        case rtl::uri::detail::EscapeOctet:
+            writeEscapeOctet(pResult, &nCapacity, nUtf32);
+            break;
+        }
+    }
+    *pResult = rtl_uStringBuffer_makeStringAndClear(pResult, &nCapacity);
+}
+
+void SAL_CALL rtl_uriDecode(rtl_uString * pText,
+                            rtl_UriDecodeMechanism eMechanism,
+                            rtl_TextEncoding eCharset, rtl_uString ** pResult)
+    SAL_THROW_EXTERN_C()
+{
+    switch (eMechanism)
+    {
+    case rtl_UriDecodeNone:
+        rtl_uString_assign(pResult, pText);
+        break;
+
+    case rtl_UriDecodeToIuri:
+        eCharset = RTL_TEXTENCODING_UTF8;
+        [[fallthrough]];
+    default: // rtl_UriDecodeWithCharset, rtl_UriDecodeStrict
+        {
+            sal_Unicode const * p = pText->buffer;
+            sal_Unicode const * pEnd = p + pText->length;
+            sal_Int32 nCapacity = pText->length;
+            rtl_uString_new_WithLength(pResult, nCapacity);
+
+            while (p < pEnd)
+            {
+                rtl::uri::detail::EscapeType eType;
+                sal_uInt32 nUtf32 = rtl::uri::detail::readUcs4(&p, pEnd, true, eCharset, &eType);
+                switch (eType)
+                {
+                case rtl::uri::detail::EscapeChar:
+                    if (nUtf32 <= 0x7F && eMechanism == rtl_UriDecodeToIuri)
+                    {
+                        writeEscapeOctet(pResult, &nCapacity, nUtf32);
+                        break;
+                    }
+                    [[fallthrough]];
+
+                case rtl::uri::detail::EscapeNo:
+                    writeUcs4(pResult, &nCapacity, nUtf32);
+                    break;
+
+                case rtl::uri::detail::EscapeOctet:
+                    if (eMechanism == rtl_UriDecodeStrict)
+                    {
+                        rtl_uString_new(pResult);
+                        return;
+                    }
+                    writeEscapeOctet(pResult, &nCapacity, nUtf32);
+                    break;
+                }
+            }
+
+            *pResult = rtl_uStringBuffer_makeStringAndClear( pResult, &nCapacity );
+        }
+        break;
+    }
+}
+
+sal_Bool SAL_CALL rtl_uriConvertRelToAbs(rtl_uString * pBaseUriRef,
+                                         rtl_uString * pRelUriRef,
+                                         rtl_uString ** pResult,
+                                         rtl_uString ** pException)
+    SAL_THROW_EXTERN_C()
+{
+    // Use the strict parser algorithm from RFC 3986, section 5.2, to turn the
+    // relative URI into an absolute one:
+    Components aRelComponents;
+    parseUriRef(pRelUriRef, &aRelComponents);
+    OUStringBuffer aBuffer(256);
+
+    if (aRelComponents.aScheme.isPresent())
+    {
+        aBuffer.append(aRelComponents.aScheme.pBegin,
+                       aRelComponents.aScheme.getLength());
+
+        if (aRelComponents.aAuthority.isPresent())
+        {
+            aBuffer.append(aRelComponents.aAuthority.pBegin,
+                           aRelComponents.aAuthority.getLength());
+        }
+
+        appendPath(
+            aBuffer, aBuffer.getLength(), false, aRelComponents.aPath.pBegin,
+            aRelComponents.aPath.pEnd);
+
+        if (aRelComponents.aQuery.isPresent())
+        {
+            aBuffer.append(aRelComponents.aQuery.pBegin,
+                           aRelComponents.aQuery.getLength());
+        }
+    }
+    else
+    {
+        Components aBaseComponents;
+        parseUriRef(pBaseUriRef, &aBaseComponents);
+        if (!aBaseComponents.aScheme.isPresent())
+        {
+            rtl_uString_assign(
+                pException,
+                (OUString(
+                    "<" + OUString::unacquired(&pBaseUriRef)
+                    + "> does not start with a scheme component")
+                 .pData));
+            return false;
+        }
+
+        aBuffer.append(aBaseComponents.aScheme.pBegin,
+                       aBaseComponents.aScheme.getLength());
+        if (aRelComponents.aAuthority.isPresent())
+        {
+            aBuffer.append(aRelComponents.aAuthority.pBegin,
+                           aRelComponents.aAuthority.getLength());
+            appendPath(
+                aBuffer, aBuffer.getLength(), false,
+                aRelComponents.aPath.pBegin, aRelComponents.aPath.pEnd);
+
+            if (aRelComponents.aQuery.isPresent())
+            {
+                aBuffer.append(aRelComponents.aQuery.pBegin,
+                               aRelComponents.aQuery.getLength());
+            }
+        }
+        else
+        {
+            if (aBaseComponents.aAuthority.isPresent())
+            {
+                aBuffer.append(aBaseComponents.aAuthority.pBegin,
+                               aBaseComponents.aAuthority.getLength());
+            }
+
+            if (aRelComponents.aPath.pBegin == aRelComponents.aPath.pEnd)
+            {
+                aBuffer.append(aBaseComponents.aPath.pBegin,
+                               aBaseComponents.aPath.getLength());
+                if (aRelComponents.aQuery.isPresent())
+                {
+                    aBuffer.append(aRelComponents.aQuery.pBegin,
+                                   aRelComponents.aQuery.getLength());
+                }
+                else if (aBaseComponents.aQuery.isPresent())
+                {
+                    aBuffer.append(aBaseComponents.aQuery.pBegin,
+                                   aBaseComponents.aQuery.getLength());
+                }
+            }
+            else
+            {
+                if (*aRelComponents.aPath.pBegin == '/')
+                {
+                    appendPath(
+                        aBuffer, aBuffer.getLength(), false,
+                        aRelComponents.aPath.pBegin, aRelComponents.aPath.pEnd);
+                }
+                else if (aBaseComponents.aAuthority.isPresent()
+                         && aBaseComponents.aPath.pBegin
+                            == aBaseComponents.aPath.pEnd)
+                {
+                    appendPath(
+                        aBuffer, aBuffer.getLength(), true,
+                        aRelComponents.aPath.pBegin, aRelComponents.aPath.pEnd);
+                }
+                else
+                {
+                    sal_Int32 n = aBuffer.getLength();
+                    sal_Int32 i = rtl_ustr_lastIndexOfChar_WithLength(
+                        aBaseComponents.aPath.pBegin,
+                        aBaseComponents.aPath.getLength(), '/');
+
+                    if (i >= 0)
+                    {
+                        appendPath(
+                            aBuffer, n, false, aBaseComponents.aPath.pBegin,
+                            aBaseComponents.aPath.pBegin + i);
+                    }
+
+                    appendPath(
+                        aBuffer, n, i >= 0, aRelComponents.aPath.pBegin,
+                        aRelComponents.aPath.pEnd);
+                }
+
+                if (aRelComponents.aQuery.isPresent())
+                {
+                    aBuffer.append(aRelComponents.aQuery.pBegin,
+                                   aRelComponents.aQuery.getLength());
+                }
+            }
+        }
+    }
+    if (aRelComponents.aFragment.isPresent())
+    {
+        aBuffer.append(aRelComponents.aFragment.pBegin,
+                       aRelComponents.aFragment.getLength());
+    }
+
+    rtl_uString_assign(pResult, aBuffer.makeStringAndClear().pData);
+    return true;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */