From e5cf5091157dcfb2874472a49368bd07012ce6f0 Mon Sep 17 00:00:00 2001
From: "Fred L. Drake, Jr." <fdrake@users.sourceforge.net>
Date: Thu, 29 Aug 2002 04:54:04 +0000
Subject: [PATCH] Revise the XML_GetFeatureList() function signature so that we
 maintain the behavior that all strings returned from Expat are affected by
 the XML_UNICODE and XML_UNICODE_WCHAR_T feature-test macros, and ensure that
 an application that needs to determine what type of character data is
 returned can do so with reasonable ease.

---
 expat/doc/reference.html | 30 ++++++++++++++++++++++++------
 expat/lib/expat.h        | 16 +++++++++++++++-
 expat/lib/xmlparse.c     | 17 +++++++++--------
 expat/xmlwf/xmlwf.c      | 10 +++++-----
 4 files changed, 53 insertions(+), 20 deletions(-)

diff --git a/expat/doc/reference.html b/expat/doc/reference.html
index 7d1d009d..1cef79bc 100644
--- a/expat/doc/reference.html
+++ b/expat/doc/reference.html
@@ -1703,20 +1703,38 @@ particular parts of the Expat API are available.
 </div>
 
 <pre class="fcndec" id="XML_GetFeatureList">
-const char **
+const XML_Feature *
 XML_GetFeatureList();
 </pre>
+<pre class="signature">
+enum XML_FeatureEnum {
+  XML_FEATURE_END = 0,
+  XML_FEATURE_UNICODE,
+  XML_FEATURE_UNICODE_WCHAR_T,
+  XML_FEATURE_DTD
+};
+
+typedef struct {
+  enum XML_FeatureEnum  feature;
+  XML_Char             *name;
+} XML_Feature;
+</pre>
 <div class="fcndef">
-<p>Returns a list of "feature" identifiers that provide details on how
+<p>Returns a list of "feature" records, providing details on how
 Expat was configured at compile time.  Most applications should not
 need to worry about this, but this information is otherwise not
 available from Expat.  This function allows code that does need to
 check these features to do so at runtime.</p>
 
-<p>The return value is an array of strings, terminated by NULL,
-identifying the feature-test macros Expat was compiled with.  Common
-features which may be found in this list include
-<code>"XML_DTD"</code> and <code>"XML_UNICODE"</code>.</p>
+<p>The return value is an array of <code>XML_Feature</code>,
+terminated by a record with a <code>feature</code> of
+<code>XML_FEATURE_END</code> and <code>name</code> of NULL,
+identifying the feature-test macros Expat was compiled with.  Since
+an application that requires this kind of information needs to
+determine the type of character the <code>name</code> points to,
+records for the <code>XML_UNICODE</code> and
+<code>XML_UNICODE_WCHAR_T</code> features will be located at the
+beginning of the list, if they are present at all.</p>
 </div>
 
 <hr />
diff --git a/expat/lib/expat.h b/expat/lib/expat.h
index ef0180a8..5a8054e3 100644
--- a/expat/lib/expat.h
+++ b/expat/lib/expat.h
@@ -870,7 +870,21 @@ typedef struct {
 XMLPARSEAPI(XML_Expat_Version)
 XML_ExpatVersionInfo(void);
 
-XMLPARSEAPI(const char **)
+/* Added in Expat 1.95.5. */
+enum XML_FeatureEnum {
+  XML_FEATURE_END = 0,
+  XML_FEATURE_UNICODE,
+  XML_FEATURE_UNICODE_WCHAR_T,
+  XML_FEATURE_DTD
+  /* Additional features must be added to the end of this enum. */
+};
+
+typedef struct {
+  enum XML_FeatureEnum  feature;
+  XML_Char             *name;
+} XML_Feature;
+
+XMLPARSEAPI(const XML_Feature *)
 XML_GetFeatureList(void);
 
 
diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
index 2d6ac3d6..2b4251d3 100644
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -1604,21 +1604,22 @@ XML_ExpatVersionInfo(void)
   return version;
 }
 
-const char **
+const XML_Feature *
 XML_GetFeatureList(void)
 {
-  static const char *features[] = {
-#ifdef XML_DTD
-    "XML_DTD",
-#endif
+  static const XML_Feature features[] = {
 #ifdef XML_UNICODE
-    "XML_UNICODE",
+    {XML_FEATURE_UNICODE,         XML_L("XML_UNICODE")},
 #endif
 #ifdef XML_UNICODE_WCHAR_T
-    "XML_UNICODE_WCHAR_T",
+    {XML_FEATURE_UNICODE_WCHAR_T, XML_L("XML_UNICODE_WCHAR_T")},
 #endif
-    NULL
+#ifdef XML_DTD
+    {XML_FEATURE_DTD,             XML_L("XML_DTD")},
+#endif
+    {XML_FEATURE_END,             NULL}
   };
+
   return features;
 }
 
diff --git a/expat/xmlwf/xmlwf.c b/expat/xmlwf/xmlwf.c
index 36d8f252..34149c34 100755
--- a/expat/xmlwf/xmlwf.c
+++ b/expat/xmlwf/xmlwf.c
@@ -599,7 +599,7 @@ showVersion(XML_Char *prog)
 {
   XML_Char *s = prog;
   XML_Char ch;
-  const char **features = XML_GetFeatureList();
+  const XML_Feature *features = XML_GetFeatureList();
   while ((ch = *s) != 0) {
     if (ch == '/'
 #ifdef WIN32
@@ -610,13 +610,13 @@ showVersion(XML_Char *prog)
     ++s;
   }
   ftprintf(stdout, T("%s using %s"), prog, XML_ExpatVersion());
-  if (features[0] == NULL)
+  if (features == NULL || features[0].feature == XML_FEATURE_END)
     ftprintf(stdout, T("\n"));
   else {
     int i = 1;
-    ftprintf(stdout, T(" (%s"), features[0]);
-    while (features[i] != NULL) {
-      ftprintf(stdout, T(", %s"), features[i]);
+    ftprintf(stdout, T(" (%s"), features[0].name);
+    while (features[i].feature != XML_FEATURE_END) {
+      ftprintf(stdout, T(", %s"), features[i].name);
       ++i;
     }
     ftprintf(stdout, T(")\n"));