[PATCH v3 3/5] msxml3: Implement ::get_attributes() for "xml" processing instruction node.

[Dmitry Timoshkov]

Signed-off-by: Dmitry Timoshkov <dmitry(a)baikal.ru>
---
 dlls/msxml3/pi.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 139 insertions(+), 1 deletion(-)

diff --git a/dlls/msxml3/pi.c b/dlls/msxml3/pi.c
index cea95708087..fe291e72af8 100644
--- a/dlls/msxml3/pi.c
+++ b/dlls/msxml3/pi.c
@@ -34,6 +34,7 @@
 #include "ole2.h"
 #include "msxml6.h"
 
+#include "xmlparser.h"
 #include "msxml_private.h"
 
 #include "wine/debug.h"
@@ -287,6 +288,138 @@ static HRESULT WINAPI dom_pi_get_nextSibling(
     return node_get_next_sibling(&This->node, domNode);
 }
 
+static HRESULT xml_get_value(xmlChar **p, xmlChar **value)
+{
+    xmlChar *v;
+    int len;
+
+    while (isspace(**p)) *p += 1;
+    if (**p != '=') return XML_E_MISSINGEQUALS;
+    *p += 1;
+
+    while (isspace(**p)) *p += 1;
+    if (**p != '"') return XML_E_MISSINGQUOTE;
+    *p += 1;
+
+    v = *p;
+    while (**p && **p != '"') *p += 1;
+    if (!**p) return XML_E_EXPECTINGCLOSEQUOTE;
+    len = *p - v;
+    if (!len) return XML_E_MISSINGNAME;
+    *p += 1;
+
+    *value = heap_alloc(len + 1);
+    if (!*value) return E_OUTOFMEMORY;
+    memcpy(*value, v, len);
+    *(*value + len) = 0;
+
+    return S_OK;
+}
+
+static void set_prop(xmlNodePtr node, xmlAttrPtr attr)
+{
+    xmlAttrPtr prop;
+
+    if (!node->properties)
+    {
+        node->properties = attr;
+        return;
+    }
+
+    prop = node->properties;
+    while (prop->next) prop = prop->next;
+
+    prop->next = attr;
+}
+
+static HRESULT parse_xml_decl(xmlNodePtr node)
+{
+    xmlChar *version, *encoding, *standalone, *p;
+    xmlAttrPtr attr;
+    HRESULT hr = S_OK;
+
+    if (!node->content) return S_OK;
+
+    version = encoding = standalone = NULL;
+
+    p = node->content;
+
+    while (*p)
+    {
+        while (isspace(*p)) p++;
+        if (!*p) break;
+
+        if (!strncmp((const char *)p, "version", 7))
+        {
+            p += 7;
+            if ((hr = xml_get_value(&p, &version)) != S_OK) goto fail;
+        }
+        else if (!strncmp((const char *)p, "encoding", 8))
+        {
+            p += 8;
+            if ((hr = xml_get_value(&p, &encoding)) != S_OK) goto fail;
+        }
+        else if (!strncmp((const char *)p, "standalone", 10))
+        {
+            p += 10;
+            if ((hr = xml_get_value(&p, &standalone)) != S_OK) goto fail;
+        }
+        else
+        {
+            FIXME("unexpected XML attribute %s\n", debugstr_a((const char *)p));
+            hr = XML_E_UNEXPECTED_ATTRIBUTE;
+            goto fail;
+        }
+    }
+
+    /* xmlSetProp/xmlSetNsProp accept only nodes of type XML_ELEMENT_NODE,
+     * so we have to create and assign attributes to a node by hand.
+     */
+
+    if (version)
+    {
+        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"version", version);
+        if (attr)
+        {
+            attr->doc = node->doc;
+            set_prop(node, attr);
+        }
+        else hr = E_OUTOFMEMORY;
+    }
+    if (encoding)
+    {
+        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"encoding", encoding);
+        if (attr)
+        {
+            attr->doc = node->doc;
+            set_prop(node, attr);
+        }
+        else hr = E_OUTOFMEMORY;
+    }
+    if (standalone)
+    {
+        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"standalone", standalone);
+        if (attr)
+        {
+            attr->doc = node->doc;
+            set_prop(node, attr);
+        }
+        else hr = E_OUTOFMEMORY;
+    }
+
+fail:
+    if (hr != S_OK)
+    {
+        xmlFreePropList(node->properties);
+        node->properties = NULL;
+    }
+
+    heap_free(version);
+    heap_free(encoding);
+    heap_free(standalone);
+    return hr;
+}
+
 static HRESULT WINAPI dom_pi_get_attributes(
     IXMLDOMProcessingInstruction *iface,
     IXMLDOMNamedNodeMap** map)
@@ -307,7 +440,12 @@ static HRESULT WINAPI dom_pi_get_attributes(
 
     if (!strcmpW(name, xmlW))
     {
-        FIXME("created dummy map for <?xml ?>\n");
+        if (!This->node.node->properties)
+        {
+            hr = parse_xml_decl(This->node.node);
+            if (hr != S_OK) return S_FALSE;
+        }
+
         *map = create_nodemap(This->node.node, &dom_pi_attr_map);
         SysFreeString(name);
         return S_OK;
-- 
2.31.1

[Nikolay Sivov]

On 4/27/21 12:27 PM, Dmitry Timoshkov wrote:
> +    /* xmlSetProp/xmlSetNsProp accept only nodes of type XML_ELEMENT_NODE,
> +     * so we have to create and assign attributes to a node by hand.
> +     */
> +
> +    if (version)
> +    {
> +        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"version", version);
> +        if (attr)
> +        {
> +            attr->doc = node->doc;
> +            set_prop(node, attr);
> +        }
> +        else hr = E_OUTOFMEMORY;
> +    }
> This is abusing libxml2 tree structure, because 'properties' is expected
> only for XML_ELEMENT_NODE nodes. I don't think we should break that
> assumption.

[Dmitry Timoshkov]

Nikolay Sivov <nsivov(a)codeweavers.com> wrote:
> On 4/27/21 12:27 PM, Dmitry Timoshkov wrote:
> > +    /* xmlSetProp/xmlSetNsProp accept only nodes of type XML_ELEMENT_NODE,
> > +     * so we have to create and assign attributes to a node by hand.
> > +     */
> > +
> > +    if (version)
> > +    {
> > +        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"version", version);
> > +        if (attr)
> > +        {
> > +            attr->doc = node->doc;
> > +            set_prop(node, attr);
> > +        }
> > +        else hr = E_OUTOFMEMORY;
> > +    }
> > This is abusing libxml2 tree structure, because 'properties' is expected
> > only for XML_ELEMENT_NODE nodes. I don't think we should break that
> > assumption.

This code carefully followes what libxml2 does itself for storing properties,
as far as I can see from the libxml2 source code this approach only leads to
using libxml2 to free properties with the node. Why do you call this an "abuse"
and think that's not acceptable? What would you suggest to use instead?

-- 
Dmitry.

[Nikolay Sivov]

On 5/7/21 9:40 AM, Dmitry Timoshkov wrote:
> Nikolay Sivov <nsivov(a)codeweavers.com> wrote:
> > On 4/27/21 12:27 PM, Dmitry Timoshkov wrote:
> > > +    /* xmlSetProp/xmlSetNsProp accept only nodes of type XML_ELEMENT_NODE,
> > > +     * so we have to create and assign attributes to a node by hand.
> > > +     */
> > > +
> > > +    if (version)
> > > +    {
> > > +        attr = xmlSetNsProp(NULL, NULL, (const xmlChar *)"version", version);
> > > +        if (attr)
> > > +        {
> > > +            attr->doc = node->doc;
> > > +            set_prop(node, attr);
> > > +        }
> > > +        else hr = E_OUTOFMEMORY;
> > > +    }
> > > This is abusing libxml2 tree structure, because 'properties' is expected
> > > only for XML_ELEMENT_NODE nodes. I don't think we should break that
> > > assumption.
> > > This code carefully followes what libxml2 does itself for storing properties,
> > > as far as I can see from the libxml2 source code this approach only leads to
> > > using libxml2 to free properties with the node. Why do you call this an "abuse"
> > > and think that's not acceptable? What would you suggest to use instead?

Because it's not meant for nodes other than elements. As far as I can
tell xmlFreeNode() won't free them for example. Similar to how <?xml ?>
is not a node in libxml2, its attributes are not properties in libxml2.