[libxslt] Fix conflict resolution for templates with same priority

[Nick Wellnhofer <nwellnhof src gnome org>]

commit b0074eeca3c6b21b4da14fdf712b853900c51635
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Wed Jul 7 00:41:00 2021 +0200

    Fix conflict resolution for templates with same priority
    
    The spec states in "5.5 Conflict Resolution for Template Rules":
    
    > It is an error if this leaves more than one matching template rule.
    > An XSLT processor may signal the error; if it does not signal the
    > error, it must recover by choosing, from amongst the matching
    > template rules that are left, the one that occurs last in the
    > stylesheet.
    
    We don't signal an error, so we must make sure to return the last
    template in the stylesheet.
    
    Fixes #55

 libxslt/pattern.c        | 23 +++++++++++++++++++----
 libxslt/xsltInternals.h  |  3 +++
 tests/REC/test-5.5-1.out |  7 +++++++
 tests/REC/test-5.5-1.xml |  7 +++++++
 tests/REC/test-5.5-1.xsl | 14 ++++++++++++++
 5 files changed, 50 insertions(+), 4 deletions(-)
---
diff --git a/libxslt/pattern.c b/libxslt/pattern.c
index 9ed750c4..22c68da8 100644
--- a/libxslt/pattern.c
+++ b/libxslt/pattern.c
@@ -2134,6 +2134,9 @@ xsltAddTemplate(xsltStylesheetPtr style, xsltTemplatePtr cur,
     if ((style == NULL) || (cur == NULL))
        return(-1);
 
+    if (cur->next != NULL)
+        cur->position = cur->next->position + 1;
+
     /* Register named template */
     if (cur->name != NULL) {
         if (style->namedTemplates == NULL) {
@@ -2495,7 +2498,10 @@ xsltGetTemplate(xsltTransformContextPtr ctxt, xmlNodePtr node,
                break;
        }
        while ((list != NULL) &&
-              ((ret == NULL)  || (list->priority > priority))) {
+              ((ret == NULL) ||
+                (list->priority > priority) ||
+                ((list->priority == priority) &&
+                 (list->template->position > ret->position)))) {
            if (xsltTestCompMatch(ctxt, list, node,
                                  ctxt->mode, ctxt->modeURI) == 1) {
                ret = list->template;
@@ -2512,7 +2518,10 @@ xsltGetTemplate(xsltTransformContextPtr ctxt, xmlNodePtr node,
            (node->type == XML_TEXT_NODE)) {
            list = curstyle->elemMatch;
            while ((list != NULL) &&
-                  ((ret == NULL)  || (list->priority > priority))) {
+                   ((ret == NULL) ||
+                    (list->priority > priority) ||
+                    ((list->priority == priority) &&
+                     (list->template->position > ret->position)))) {
                if (xsltTestCompMatch(ctxt, list, node,
                                      ctxt->mode, ctxt->modeURI) == 1) {
                    ret = list->template;
@@ -2525,7 +2534,10 @@ xsltGetTemplate(xsltTransformContextPtr ctxt, xmlNodePtr node,
                   (node->type == XML_COMMENT_NODE)) {
            list = curstyle->elemMatch;
            while ((list != NULL) &&
-                  ((ret == NULL)  || (list->priority > priority))) {
+                   ((ret == NULL) ||
+                    (list->priority > priority) ||
+                    ((list->priority == priority) &&
+                     (list->template->position > ret->position)))) {
                if (xsltTestCompMatch(ctxt, list, node,
                                      ctxt->mode, ctxt->modeURI) == 1) {
                    ret = list->template;
@@ -2540,7 +2552,10 @@ keyed_match:
        if (keyed) {
            list = curstyle->keyMatch;
            while ((list != NULL) &&
-                  ((ret == NULL)  || (list->priority > priority))) {
+                   ((ret == NULL) ||
+                    (list->priority > priority) ||
+                    ((list->priority == priority) &&
+                     (list->template->position > ret->position)))) {
                if (xsltTestCompMatch(ctxt, list, node,
                                      ctxt->mode, ctxt->modeURI) == 1) {
                    ret = list->template;
diff --git a/libxslt/xsltInternals.h b/libxslt/xsltInternals.h
index 946e43c5..14343d27 100644
--- a/libxslt/xsltInternals.h
+++ b/libxslt/xsltInternals.h
@@ -291,6 +291,9 @@ struct _xsltTemplate {
     int              templMax;         /* Size of the templtes stack */
     xsltTemplatePtr *templCalledTab;   /* templates called */
     int             *templCountTab;  /* .. and how often */
+
+    /* Conflict resolution */
+    int position;
 };
 
 /**
diff --git a/tests/REC/test-5.5-1.out b/tests/REC/test-5.5-1.out
new file mode 100644
index 00000000..8f353180
--- /dev/null
+++ b/tests/REC/test-5.5-1.out
@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<winelist>
+  <wine>
+    <winery>Benziger</winery>
+    <product>Carneros</product>
+  </wine>
+</winelist>
diff --git a/tests/REC/test-5.5-1.xml b/tests/REC/test-5.5-1.xml
new file mode 100644
index 00000000..874a183e
--- /dev/null
+++ b/tests/REC/test-5.5-1.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<winelist>
+  <wine grape="Chardonnay">
+    <winery>Benziger</winery>
+    <product>Carneros</product>
+  </wine>
+</winelist>
diff --git a/tests/REC/test-5.5-1.xsl b/tests/REC/test-5.5-1.xsl
new file mode 100644
index 00000000..7c00d92f
--- /dev/null
+++ b/tests/REC/test-5.5-1.xsl
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- transformation of the calloutlist element -->
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
+
+  <xsl:template match="text()">
+  </xsl:template>
+
+  <xsl:template match="@*|node()">
+    <xsl:copy>
+      <xsl:apply-templates/>
+    </xsl:copy>
+  </xsl:template>
+
+</xsl:stylesheet>