[libxml2] A few more safety cleanup raised by scan

[Daniel Veillard <veillard src gnome org>]

commit d44b9364991bd0067d50c29bdff48305dfdad4ce
Author: Daniel Veillard <veillard redhat com>
Date:   Mon Sep 7 12:15:08 2009 +0200

    A few more safety cleanup raised by scan
    
    * SAX2.c encoding.c parser.c xmlschemas.c: a few more safety checks
    * relaxng.c: remove an unused intitialization

 SAX2.c       |   40 +++++++++++++++++++++-------------------
 encoding.c   |   15 +++++++++------
 parser.c     |   21 ++++++++++++++++-----
 relaxng.c    |    5 ++++-
 xmlschemas.c |    3 ++-
 5 files changed, 52 insertions(+), 32 deletions(-)
---
diff --git a/SAX2.c b/SAX2.c
index 94b39d4..1cf186a 100644
--- a/SAX2.c
+++ b/SAX2.c
@@ -1246,30 +1246,32 @@ xmlSAX2AttributeInternal(void *ctx, const xmlChar *fullname,
     }
 
     if (ns != NULL) {
-	xmlAttrPtr prop;
 	namespace = xmlSearchNs(ctxt->myDoc, ctxt->node, ns);
+
 	if (namespace == NULL) {
 	    xmlNsErrMsg(ctxt, XML_NS_ERR_UNDEFINED_NAMESPACE,
 		    "Namespace prefix %s of attribute %s is not defined\n",
 		             ns, name);
-	}
-
-	prop = ctxt->node->properties;
-	while (prop != NULL) {
-	    if (prop->ns != NULL) {
-		if ((xmlStrEqual(name, prop->name)) &&
-		    ((namespace == prop->ns) ||
-		     (xmlStrEqual(namespace->href, prop->ns->href)))) {
-			xmlNsErrMsg(ctxt, XML_ERR_ATTRIBUTE_REDEFINED,
-			        "Attribute %s in %s redefined\n",
-			                 name, namespace->href);
-		    ctxt->wellFormed = 0;
-		    if (ctxt->recovery == 0) ctxt->disableSAX = 1;
-		    goto error;
-		}
-	    }
-	    prop = prop->next;
-	}
+	} else {
+            xmlAttrPtr prop;
+
+            prop = ctxt->node->properties;
+            while (prop != NULL) {
+                if (prop->ns != NULL) {
+                    if ((xmlStrEqual(name, prop->name)) &&
+                        ((namespace == prop->ns) ||
+                         (xmlStrEqual(namespace->href, prop->ns->href)))) {
+                            xmlNsErrMsg(ctxt, XML_ERR_ATTRIBUTE_REDEFINED,
+                                    "Attribute %s in %s redefined\n",
+                                             name, namespace->href);
+                        ctxt->wellFormed = 0;
+                        if (ctxt->recovery == 0) ctxt->disableSAX = 1;
+                        goto error;
+                    }
+                }
+                prop = prop->next;
+            }
+        }
     } else {
 	namespace = NULL;
     }
diff --git a/encoding.c b/encoding.c
index d48c757..b86a547 100644
--- a/encoding.c
+++ b/encoding.c
@@ -1602,14 +1602,17 @@ xmlFindCharEncodingHandler(const char *name) {
     }
     upper[i] = 0;
 
-    for (i = 0;i < nbCharEncodingHandler; i++)
-        if (!strcmp(upper, handlers[i]->name)) {
+    if (handlers != NULL) {
+        for (i = 0;i < nbCharEncodingHandler; i++) {
+            if (!strcmp(upper, handlers[i]->name)) {
 #ifdef DEBUG_ENCODING
-            xmlGenericError(xmlGenericErrorContext,
-		    "Found registered handler for encoding %s\n", name);
+                xmlGenericError(xmlGenericErrorContext,
+                        "Found registered handler for encoding %s\n", name);
 #endif
-	    return(handlers[i]);
-	}
+                return(handlers[i]);
+            }
+        }
+    }
 
 #ifdef LIBXML_ICONV_ENABLED
     /* check whether iconv can handle this */
diff --git a/parser.c b/parser.c
index 5337541..1e4164a 100644
--- a/parser.c
+++ b/parser.c
@@ -524,13 +524,21 @@ xmlWarningMsg(xmlParserCtxtPtr ctxt, xmlParserErrors error,
     if ((ctxt != NULL) && (ctxt->sax != NULL) &&
         (ctxt->sax->initialized == XML_SAX2_MAGIC))
         schannel = ctxt->sax->serror;
-    __xmlRaiseError(schannel,
+    if (ctxt != NULL) {
+        __xmlRaiseError(schannel,
                     (ctxt->sax) ? ctxt->sax->warning : NULL,
                     ctxt->userData,
                     ctxt, NULL, XML_FROM_PARSER, error,
                     XML_ERR_WARNING, NULL, 0,
 		    (const char *) str1, (const char *) str2, NULL, 0, 0,
 		    msg, (const char *) str1, (const char *) str2);
+    } else {
+        __xmlRaiseError(schannel, NULL, NULL,
+                    ctxt, NULL, XML_FROM_PARSER, error,
+                    XML_ERR_WARNING, NULL, 0,
+		    (const char *) str1, (const char *) str2, NULL, 0, 0,
+		    msg, (const char *) str1, (const char *) str2);
+    }
 }
 
 /**
@@ -5773,7 +5781,8 @@ xmlParseElementMixedContentDecl(xmlParserCtxtPtr ctxt, int inputchk) {
 		if (cur->c2 != NULL)
 		    cur->c2->parent = cur;
             }
-	    ret->ocur = XML_ELEMENT_CONTENT_MULT;
+            if (ret != NULL)
+                ret->ocur = XML_ELEMENT_CONTENT_MULT;
 	    if ((ctxt->validate) && (ctxt->input->id != inputchk)) {
 		xmlValidityError(ctxt, XML_ERR_ENTITY_BOUNDARY,
 "Element content declaration doesn't start and stop in the same entity\n",
@@ -8370,7 +8379,7 @@ xmlParseQName(xmlParserCtxtPtr ctxt, const xmlChar **prefix) {
 static const xmlChar *
 xmlParseQNameAndCompare(xmlParserCtxtPtr ctxt, xmlChar const *name,
                         xmlChar const *prefix) {
-    const xmlChar *cmp = name;
+    const xmlChar *cmp;
     const xmlChar *in;
     const xmlChar *ret;
     const xmlChar *prefix2;
@@ -8379,7 +8388,7 @@ xmlParseQNameAndCompare(xmlParserCtxtPtr ctxt, xmlChar const *name,
 
     GROW;
     in = ctxt->input->cur;
-    
+
     cmp = prefix;
     while (*in != 0 && *in == *cmp) {
     	++in;
@@ -12768,7 +12777,9 @@ xmlParseBalancedChunkMemoryInternal(xmlParserCtxtPtr oldctxt,
      * Record in the parent context the number of entities replacement
      * done when parsing that reference.
      */
-    oldctxt->nbentities += ctxt->nbentities;
+    if (oldctxt != NULL)
+        oldctxt->nbentities += ctxt->nbentities;
+
     /*
      * Also record the last error if any
      */
diff --git a/relaxng.c b/relaxng.c
index 351f03a..5146d9d 100644
--- a/relaxng.c
+++ b/relaxng.c
@@ -3470,6 +3470,9 @@ xmlRelaxNGGetDataTypeLibrary(xmlRelaxNGParserCtxtPtr ctxt ATTRIBUTE_UNUSED,
 {
     xmlChar *ret, *escape;
 
+    if (node == NULL)
+        return(NULL);
+
     if ((IS_RELAXNG(node, "data")) || (IS_RELAXNG(node, "value"))) {
         ret = xmlGetProp(node, BAD_CAST "datatypeLibrary");
         if (ret != NULL) {
@@ -6229,7 +6232,7 @@ xmlRelaxNGCheckRules(xmlRelaxNGParserCtxtPtr ctxt,
                      xmlRelaxNGDefinePtr cur, int flags,
                      xmlRelaxNGType ptype)
 {
-    int nflags = flags;
+    int nflags;
     xmlRelaxNGContentType ret, tmp, val = XML_RELAXNG_CONTENT_EMPTY;
 
     while (cur != NULL) {
diff --git a/xmlschemas.c b/xmlschemas.c
index e79d5a0..acc1f78 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -15635,7 +15635,8 @@ xmlSchemaCheckCOSSTRestricts(xmlSchemaParserCtxtPtr pctxt,
 			    return (XML_SCHEMAP_COS_ST_RESTRICTS_3_3_2_3);
 			}
 			member = member->next;
-			baseMember = baseMember->next;
+                        if (baseMember != NULL)
+                            baseMember = baseMember->next;
 		    }
 		}
 	    }