[PATCH v3 0/1] MR1334: xmllite/writer: Handle surrogate pairs

[David Kahurani (＠kahurani)]

Surrogates have to be written in pairs. Also, handle related errors

Signed-off-by: David Kahurani

--
  v3: xmllite/writer: Handle surrogate pairs

https://gitlab.winehq.org/wine/wine/-/merge_requests/1334

[PATCH v3 1/1] xmllite/writer: Handle surrogate pairs

[David Kahurani]

From: David Kahurani

Surrogates have to be written in pairs. Also, handle related errors.

Signed-off-by: David Kahurani 
---
 dlls/xmllite/reader.c          | 10 ------
 dlls/xmllite/tests/writer.c    | 20 ++++++++++++
 dlls/xmllite/writer.c          | 59 ++++++++++++++++++++++++++++++----
 dlls/xmllite/xmllite_private.h |  9 ++++++
 4 files changed, 81 insertions(+), 17 deletions(-)

diff --git a/dlls/xmllite/reader.c b/dlls/xmllite/reader.c
index d747e36e623..f238e2af79d 100644
--- a/dlls/xmllite/reader.c
+++ b/dlls/xmllite/reader.c
@@ -1466,16 +1466,6 @@ static HRESULT reader_parse_comment(xmlreader *reader)
     return S_OK;
 }

-/* [2] Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] */
-static inline BOOL is_char(WCHAR ch)
-{
-    return (ch == '\t') || (ch == '\r') || (ch == '\n') ||
-           (ch >= 0x20 && ch <= 0xd7ff) ||
-           (ch >= 0xd800 && ch <= 0xdbff) || /* high surrogate */
-           (ch >= 0xdc00 && ch <= 0xdfff) || /* low surrogate */
-           (ch >= 0xe000 && ch <= 0xfffd);
-}
-
 /* [13] PubidChar ::= #x20 | #xD | #xA | [a-zA-Z0-9] | [-'()+,./:=?;!*#@$_%] */
 BOOL is_pubchar(WCHAR ch)
 {
diff --git a/dlls/xmllite/tests/writer.c b/dlls/xmllite/tests/writer.c
index c4ab079373c..1777bf0f40e 100644
--- a/dlls/xmllite/tests/writer.c
+++ b/dlls/xmllite/tests/writer.c
@@ -1339,6 +1339,7 @@ static void test_WriteRaw(void)
     IXmlWriter *writer;
     IStream *stream;
     HRESULT hr;
+    WCHAR surrogates[] = {0xdc00, 0xd800, '\0'};

hr = CreateXmlWriter(&IID_IXmlWriter, (void**)&writer, NULL);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
@@ -1351,6 +1352,9 @@ static void test_WriteRaw(void)

stream = writer_set_output(writer);

+    hr = IXmlWriter_WriteRaw(writer, surrogates);
+    ok(hr == WR_E_INVALIDSURROGATEPAIR, "Unexpected hr %#lx.\n", hr);
+
     hr = IXmlWriter_WriteRaw(writer, NULL);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);

@@ -1888,6 +1892,7 @@ static void test_WriteString(void)
     IXmlWriter *writer;
     IStream *stream;
     HRESULT hr;
+    WCHAR surrogates[] = {0xd800, 0xdc00, 'x', 'y', '\0'};

hr = CreateXmlWriter(&IID_IXmlWriter, (void**)&writer, NULL);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
@@ -1905,6 +1910,21 @@ static void test_WriteString(void)

stream = writer_set_output(writer);

+    hr = IXmlWriter_WriteStartElement(writer, NULL, L"sub", NULL);
+    ok(hr == S_OK, "Unexpected hr #%lx.\n", hr);
+
+    hr = IXmlWriter_WriteString(writer, surrogates);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+
+    hr = IXmlWriter_Flush(writer);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+
+    CHECK_OUTPUT(stream,
+        "<sub>\U00010000xy");
+    IStream_Release(stream);
+
+    stream = writer_set_output(writer);
+
     hr = IXmlWriter_WriteStartElement(writer, NULL, L"b", NULL);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);

diff --git a/dlls/xmllite/writer.c b/dlls/xmllite/writer.c
index 065716f7e8c..a1aaec974cc 100644
--- a/dlls/xmllite/writer.c
+++ b/dlls/xmllite/writer.c
@@ -163,6 +163,16 @@ static inline void *writer_alloc(const xmlwriter *writer, size_t len)
     return m_alloc(writer->imalloc, len);
 }

+static BOOL is_high_surrogate(WCHAR ch)
+{
+    return ch >= 0xd800 && ch <= 0xdbff;
+}
+
+static BOOL is_low_surrogate(WCHAR ch)
+{
+    return ch >= 0xdc00 && ch <= 0xdfff;
+}
+
 static inline void writer_free(const xmlwriter *writer, void *mem)
 {
     m_free(writer->imalloc, mem);
@@ -1684,6 +1694,31 @@ static HRESULT WINAPI xmlwriter_WriteQualifiedName(IXmlWriter *iface, LPCWSTR pw
     return E_NOTIMPL;
 }

+static HRESULT write_raw_char(xmlwriteroutput *output, LPCWSTR *context)
+{
+    const WCHAR *data = *context;
+
+    if (!is_char(*data)) return WC_E_XMLCHARACTER;
+
+    if (is_high_surrogate(*data))
+    {
+        if (!is_low_surrogate(*(data + 1)))
+            return WR_E_INVALIDSURROGATEPAIR;
+
+        write_output_buffer(output, data, 2);
+	(*context) += 2;
+    }
+    else if (is_low_surrogate(*data))
+	return WR_E_INVALIDSURROGATEPAIR;
+    else
+    {
+        write_output_buffer(output, data, 1);
+        (*context)++;
+    }
+
+    return S_OK;
+}
+
 static HRESULT WINAPI xmlwriter_WriteRaw(IXmlWriter *iface, LPCWSTR data)
 {
     xmlwriter *This = impl_from_IXmlWriter(iface);
@@ -1713,7 +1748,12 @@ static HRESULT WINAPI xmlwriter_WriteRaw(IXmlWriter *iface, LPCWSTR data)
         return WR_E_INVALIDACTION;
     }

-    write_output_buffer(This->output, data, -1);
+    while (*data)
+    {
+        HRESULT hr = write_raw_char(This->output, &data);
+        if (FAILED(hr)) return hr;
+    }
+
     return S_OK;
 }

@@ -1834,7 +1874,7 @@ static HRESULT WINAPI xmlwriter_WriteStartElement(IXmlWriter *iface, LPCWSTR pre
     return S_OK;
 }

-static void write_escaped_string(xmlwriter *writer, const WCHAR *string)
+static HRESULT write_escaped_string(xmlwriter *writer, const WCHAR *string)
 {
     while (*string)
     {
@@ -1842,19 +1882,25 @@ static void write_escaped_string(xmlwriter *writer, const WCHAR *string)
         {
         case '<':
             write_output_buffer(writer->output, L"&lt;", 4);
+            string++;
             break;
         case '&':
             write_output_buffer(writer->output, L"&amp;", 5);
+            string++;
             break;
         case '>':
             write_output_buffer(writer->output, L"&gt;", 4);
+            string++;
             break;
         default:
-            write_output_buffer(writer->output, string, 1);
+	    {
+                HRESULT hr = write_raw_char(writer->output, &string);
+		if (FAILED(hr)) return hr;
+	    }
         }
-
-        string++;
     }
+
+    return S_OK;
 }

static HRESULT WINAPI xmlwriter_WriteString(IXmlWriter *iface, const WCHAR *string)
@@ -1884,8 +1930,7 @@ static HRESULT WINAPI xmlwriter_WriteString(IXmlWriter *iface, const WCHAR *stri
     }

This->textnode = 1;
-    write_escaped_string(This, string);
-    return S_OK;
+    return write_escaped_string(This, string);
 }

static HRESULT WINAPI xmlwriter_WriteSurrogateCharEntity(IXmlWriter *iface, WCHAR wchLow, WCHAR wchHigh)
diff --git a/dlls/xmllite/xmllite_private.h b/dlls/xmllite/xmllite_private.h
index bd53fca575f..45993d20567 100644
--- a/dlls/xmllite/xmllite_private.h
+++ b/dlls/xmllite/xmllite_private.h
@@ -68,4 +68,13 @@ static inline BOOL is_wchar_space(WCHAR ch)
     return ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n';
 }

+/* [2] Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] */
+static inline BOOL is_char(WCHAR ch)
+{
+    return (ch == '\t') || (ch == '\r') || (ch == '\n') ||
+           (ch >= 0x20 && ch <= 0xd7ff) ||
+           (ch >= 0xd800 && ch <= 0xdbff) || /* high surrogate */
+           (ch >= 0xdc00 && ch <= 0xdfff) || /* low surrogate */
+           (ch >= 0xe000 && ch <= 0xfffd);
+}
 #endif /* __XMLLITE_PRIVATE__ */

[Alex Henrie (＠alexhenrie)]

Alex Henrie (@alexhenrie) commented about dlls/xmllite/tests/writer.c:
>  IXmlWriter *writer;
>  IStream *stream;
>  HRESULT hr;
> - WCHAR surrogates[] = {0xdc00, 0xd800, '\0'};

This variable could be `static const`.

[Alex Henrie (＠alexhenrie)]

Alex Henrie (@alexhenrie) commented about dlls/xmllite/tests/writer.c:
>  IXmlWriter *writer;
>  IStream *stream;
>  HRESULT hr;
> - WCHAR surrogates[] = {0xd800, 0xdc00, 'x', 'y', '\0'};

This variable could also be `static const`.