changed handling of function params to fix bug #381319 exposed

* libexslt/functions.c: changed handling of function params
  to fix bug #381319
* libxslt/transform.[ch]: exposed xsltLocalVariablePush and
  xsltLocalVariablePop as global entries so that they could
  be used from within libexslt/functions.c
* tests/exslt/functions/function.9.[xsl,xml,out] added to
  regression tests

ChangeLog

+Sat Dec  9 15:22:34 PST 2006 William Brack <wbrack@mmm.com.hk>
+
+	* libexslt/functions.c: changed handling of function params
+	  to fix bug #381319
+	* libxslt/transform.[ch]: exposed xsltLocalVariablePush and
+	  xsltLocalVariablePop as global entries so that they could
+	  be used from within libexslt/functions.c
+	* tests/exslt/functions/function.9.[xsl,xml,out] added to
+	  regression tests
+
 Tue Dec  5 10:45:04 CET 2006 Daniel Veillard <daniel@veillard.com>
 
 	* libxslt/extensions.c: applied patch from Marcus Meissner removing

libexslt/functions.c

@@ -281,7 +281,7 @@
     int oldBase;
     xsltStackElemPtr params = NULL, param;
     xsltTransformContextPtr tctxt = xsltXPathGetTransformContext(ctxt);
-    int i;
+    int i, notSet;;
 
     /*
      * retrieve func:function template
@@ -317,6 +317,6 @@
 	return;
     }
     /* 
-    * Process xsl:param instructions which were not set by the
-    * invoking function call.
+     * In order to give the function params and variables a new 'scope'
+     * we change varsBase in the context.
      */
@@ -322,3 +322,7 @@
      */
-    for (i = func->nargs; (i > nargs) && (paramNode != NULL); i--) {
+    oldBase = tctxt->varsBase;
+    tctxt->varsBase = tctxt->varsNr;
+
+    /* If there are any parameters */
+    if (paramNode != NULL) {
 	/*
@@ -324,4 +328,6 @@
 	/*
-	* Those are the xsl:param instructions, which were not
-	* set by the calling function.	
+	 * We need to process params which have been set by the invoking
+	 * function call before those which were not (in case the set values
+	 * are used within non-set 'select' default values), so we position
+	 * to the beginning of the params.
 	 */
@@ -327,7 +333,7 @@
 	 */
-	param = xsltParseStylesheetCallerParam (tctxt, paramNode);
-	param->next = params;
-	params = param;
+	for (i = 1; i <= func->nargs; i++) {
+    	    if (paramNode->prev == NULL)
+		break;
 	    paramNode = paramNode->prev;
 	}
 	/*
@@ -331,6 +337,6 @@
 	    paramNode = paramNode->prev;
 	}
 	/*
-    * Process xsl:param instructions which are set by the
-    * invoking function call.
+	 * i has total # params found, nargs is number which are present
+	 * as arguments from the caller
 	 */
@@ -336,3 +342,5 @@
 	 */
-    while ((i-- > 0) && (paramNode != NULL)) {
+	notSet = func->nargs - nargs;
+	for (; i > 0; i--) {
+	    if (i > notSet) 	/* if parameter value set */
 	        obj = valuePop(ctxt);
@@ -338,12 +346,2 @@
 	        obj = valuePop(ctxt);
-	/*
-	* TODO: Using xsltParseStylesheetCallerParam() is actually
-	* not correct, since we are processing an xsl:param; but
-	* using xsltParseStylesheetParam() won't work, as it puts
-	* the param on the varible stack and does not give access to
-	* the created xsltStackElemPtr.
-	* It's also not correct, as xsltParseStylesheetCallerParam()
-	* will report error messages indicating an "xsl:with-param" and
-	* not the actual "xsl:param".
-	*/
 	    param = xsltParseStylesheetCallerParam (tctxt, paramNode);
@@ -349,5 +347,6 @@
 	    param = xsltParseStylesheetCallerParam (tctxt, paramNode);
+	    if (i > notSet) {	/* if parameter value set */
 		param->computed = 1;
 		if (param->value != NULL)
 		    xmlXPathFreeObject(param->value);
 		param->value = obj;
@@ -350,6 +349,8 @@
 		param->computed = 1;
 		if (param->value != NULL)
 		    xmlXPathFreeObject(param->value);
 		param->value = obj;
+	    }
+	    xsltLocalVariablePush(tctxt, param, -1);
 	    param->next = params;
 	    params = param;
@@ -354,4 +355,4 @@
 	    param->next = params;
 	    params = param;
-	paramNode = paramNode->prev;
+	    paramNode = paramNode->next;
 	}
@@ -357,5 +358,5 @@
 	}
-    
+    }
     /*
      * actual processing
      */
@@ -363,10 +364,4 @@
 			 (const xmlChar *)"fake", NULL);
     oldInsert = tctxt->insert;
     tctxt->insert = fake;
-    /* 
-     * In order to give the function variables a new 'scope' we
-     * change varsBase in the context.
-     */
-    oldBase = tctxt->varsBase;
-    tctxt->varsBase = tctxt->varsNr;
     xsltApplyOneTemplate (tctxt, xmlXPathGetContextNode(ctxt),
@@ -372,5 +367,6 @@
     xsltApplyOneTemplate (tctxt, xmlXPathGetContextNode(ctxt),
-			  func->content, NULL, params);
+			  func->content, NULL, NULL);
+    xsltLocalVariablePop(tctxt, tctxt->varsBase, -2);
     tctxt->insert = oldInsert;
     tctxt->varsBase = oldBase;	/* restore original scope */
     if (params != NULL)

libxslt/transform.c

@@ -173,8 +173,10 @@
  * Pops all variable values at the given @depth from the stack.
  *
  * Returns the stored variable value
- */
-static void
+ * **NOTE:**
+ * This is an internal routine and should not be called by users!
+ */
+void
 xsltLocalVariablePop(xsltTransformContextPtr ctxt, int limitNr, int level)
 {
     xsltStackElemPtr variable;
@@ -2067,7 +2069,19 @@
     return(debugedNode);
 }
 
-static int
+/**
+ * xsltVariablePush:
+ * @ctxt: the transformation context
+ * @variable: variable to be pushed to the variable stack
+ * @level: new value for variable's level
+ *
+ * Places the variable onto the local variable stack
+ *
+ * Returns: 0 for success, -1 for any error
+ * **NOTE:**
+ * This is an internal routine and should not be called by users!
+ */
+int
 xsltLocalVariablePush(xsltTransformContextPtr ctxt,
 		      xsltStackElemPtr variable,
 		      int level)
@@ -3132,6 +3146,11 @@
     CHECK_STOPPED;
 
     if (params) {
+	/*
+	 * This code should be obsolete - was previously used
+	 * by libexslt/functions.c, but due to bug 381319 the
+	 * logic there was changed.
+	 */
 	int oldVarsNr = ctxt->varsNr;
 
 	/*

libxslt/transform.h

@@ -176,6 +176,16 @@
 					 xmlNodePtr target,
 					 const xmlChar *string,
 					 int noescape);
+
+/* Following 2 functions needed for libexslt/functions.c */
+XSLTPUBFUN void XSLTCALL
+		xsltLocalVariablePop	(xsltTransformContextPtr ctxt,
+					 int limitNr,
+					 int level);
+XSLTPUBFUN int XSLTCALL
+		xsltLocalVariablePush	(xsltTransformContextPtr ctxt,
+					 xsltStackElemPtr variable,
+					 int level);
 /*
  * Hook for the debugger if activated.
  */

tests/exslt/functions/Makefile.am

@@ -11,7 +11,8 @@
 	function.5.out  function.5.xml  function.5.xsl  \
 	function.6.out  function.6.xml  function.6.xsl  \
 	function.7.out  function.7.xml  function.7.xsl  \
-	function.8.out  function.8.xml  function.8.xsl
+	function.8.out  function.8.xml  function.8.xsl  \
+	function.9.out  function.9.xml  function.9.xsl
 
 all:
 

tests/exslt/functions/function.9.out

+<?xml version="1.0"?>
+
+  
+      a                 
+    
+

tests/exslt/functions/function.9.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<root>
+  <table>
+    <tr>
+      <td align="center">a</td>                 
+    </tr>
+  </table>
+</root>
+

tests/exslt/functions/function.9.xsl

+<?xml version="1.0" encoding="UTF-8"?>
+<xsl:stylesheet version="1.0"
+  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+  xmlns:exsl="http://exslt.org/common"
+  xmlns:func="http://exslt.org/functions"
+  xmlns:math="http://exslt.org/math"
+  xmlns:mg="mg"
+  extension-element-prefixes="exsl func">
+
+  <xsl:template match="table">          
+    <xsl:variable name="cols" select="mg:function(.)"/>         
+    <xsl:value-of select="$cols"/>
+  </xsl:template>       
+
+  <func:function name="mg:function">
+    <xsl:param name="table"/>
+    <xsl:param name="tr" select="$table/tr[1]"/>                
+    <func:result select="$tr"/>
+  </func:function>      
+</xsl:stylesheet>
+
+