[libxslt] Allow {URI}NCName syntax for user parameters

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 891681e3e948f31732229f53cb6db7215f740fc7
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Mon Mar 28 16:02:18 2016 +0200

    Allow {URI}NCName syntax for user parameters
    
    Thanks to Richard Smith <richard ex-parrot com> for the patch. Applied
    with minor changes.
    
    Fixes bug #764195.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=764195

 libxslt/variables.c |   42 ++++++++++++++++++++++++++++--------------
 xsltproc/xsltproc.c |    1 +
 2 files changed, 29 insertions(+), 14 deletions(-)
---
diff --git a/libxslt/variables.c b/libxslt/variables.c
index 3224116..345123d 100644
--- a/libxslt/variables.c
+++ b/libxslt/variables.c
@@ -1445,21 +1445,35 @@ xsltProcessUserParamInternal(xsltTransformContextPtr ctxt,
     /*
      * Name lookup
      */
-
-    name = xsltSplitQName(ctxt->dict, name, &prefix);
     href = NULL;
-    if (prefix != NULL) {
-       xmlNsPtr ns;
 
-       ns = xmlSearchNs(style->doc, xmlDocGetRootElement(style->doc),
-                        prefix);
-       if (ns == NULL) {
-           xsltTransformError(ctxt, style, NULL,
-           "user param : no namespace bound to prefix %s\n", prefix);
-           href = NULL;
-       } else {
-           href = ns->href;
-       }
+    if (name[0] == '{') {
+        int len = 0;
+
+        while ((name[len] != 0) && (name[len] != '}')) len++;
+        if (name[len] == 0) {
+           xsltTransformError(ctxt, style, NULL,
+           "user param : malformed parameter name : %s\n", name);
+        } else {
+           href = xmlDictLookup(ctxt->dict, &name[1], len-1);
+           name = xmlDictLookup(ctxt->dict, &name[len + 1], -1);
+       }
+    }
+    else {
+        name = xsltSplitQName(ctxt->dict, name, &prefix);
+        if (prefix != NULL) {
+            xmlNsPtr ns;
+
+            ns = xmlSearchNs(style->doc, xmlDocGetRootElement(style->doc),
+                             prefix);
+            if (ns == NULL) {
+                xsltTransformError(ctxt, style, NULL,
+                "user param : no namespace bound to prefix %s\n", prefix);
+                href = NULL;
+            } else {
+                href = ns->href;
+            }
+        }
     }
 
     if (name == NULL)
diff --git a/xsltproc/xsltproc.c b/xsltproc/xsltproc.c
index ead3893..3c83abd 100644
--- a/xsltproc/xsltproc.c
+++ b/xsltproc/xsltproc.c
@@ -523,6 +523,7 @@ static void usage(const char *name) {
 #endif
     printf("\t--encoding: the input document character encoding\n");
     printf("\t--param name value : pass a (parameter,value) pair\n");
+    printf("\t       name is a QName or a string of the form {URI}NCName.\n");
     printf("\t       value is an UTF8 XPath expression.\n");
     printf("\t       string values must be quoted like \"'string'\"\n or");
     printf("\t       use stringparam to avoid it\n");