Roll libxml to bdec2183f34b37ee89ae1d330c6ad2bb4d76605f

third_party/libxml/src/xmlstring.c

Index: third_party/libxml/src/xmlstring.c
diff --git a/third_party/libxml/src/xmlstring.c b/third_party/libxml/src/xmlstring.c
index b6dd10121845c39d114ada3af3b61ea8f5a6b134..9e704a9f346ba05aae7e4be6d304453d8a7d3967 100644
--- a/third_party/libxml/src/xmlstring.c
+++ b/third_party/libxml/src/xmlstring.c
@@ -457,6 +457,8 @@ xmlStrncat(xmlChar *cur, const xmlChar *add, int len) {
         return(xmlStrndup(add, len));
 
     size = xmlStrlen(cur);
+    if (size < 0)
+        return(NULL);
     ret = (xmlChar *) xmlRealloc(cur, (size + len + 1) * sizeof(xmlChar));
     if (ret == NULL) {
         xmlErrMemory(NULL, NULL);
@@ -484,14 +486,19 @@ xmlStrncatNew(const xmlChar *str1, const xmlChar *str2, int len) {
     int size;
     xmlChar *ret;
 
-    if (len < 0)
+    if (len < 0) {
         len = xmlStrlen(str2);
+        if (len < 0)
+            return(NULL);
+    }
     if ((str2 == NULL) || (len == 0))
         return(xmlStrdup(str1));
     if (str1 == NULL)
         return(xmlStrndup(str2, len));
 
     size = xmlStrlen(str1);
+    if (size < 0)
+        return(NULL);
     ret = (xmlChar *) xmlMalloc((size + len + 1) * sizeof(xmlChar));
     if (ret == NULL) {
         xmlErrMemory(NULL, NULL);
@@ -538,7 +545,7 @@ xmlStrcat(xmlChar *cur, const xmlChar *add) {
  * Returns the number of characters written to @buf or -1 if an error occurs.
  */
 int XMLCDECL
-xmlStrPrintf(xmlChar *buf, int len, const xmlChar *msg, ...) {
+xmlStrPrintf(xmlChar *buf, int len, const char *msg, ...) {
     va_list args;
     int ret;
 
@@ -566,7 +573,7 @@ xmlStrPrintf(xmlChar *buf, int len, const xmlChar *msg, ...) {
  * Returns the number of characters written to @buf or -1 if an error occurs.
  */
 int
-xmlStrVPrintf(xmlChar *buf, int len, const xmlChar *msg, va_list ap) {
+xmlStrVPrintf(xmlChar *buf, int len, const char *msg, va_list ap) {
     int ret;
 
     if((buf == NULL) || (msg == NULL)) {
@@ -984,5 +991,60 @@ xmlUTF8Strsub(const xmlChar *utf, int start, int len) {
     return(xmlUTF8Strndup(utf, len));
 }
 
+/**
+ * xmlEscapeFormatString:
+ * @msg:  a pointer to the string in which to escape '%' characters.
+ * Must be a heap-allocated buffer created by libxml2 that may be
+ * returned, or that may be freed and replaced.
+ *
+ * Replaces the string pointed to by 'msg' with an escaped string.
+ * Returns the same string with all '%' characters escaped.
+ */
+xmlChar *
+xmlEscapeFormatString(xmlChar **msg)
+{
+    xmlChar *msgPtr = NULL;
+    xmlChar *result = NULL;
+    xmlChar *resultPtr = NULL;
+    size_t count = 0;
+    size_t msgLen = 0;
+    size_t resultLen = 0;
+
+    if (!msg || !*msg)
+        return(NULL);
+
+    for (msgPtr = *msg; *msgPtr != '\0'; ++msgPtr) {
+        ++msgLen;
+        if (*msgPtr == '%')
+            ++count;
+    }
+
+    if (count == 0)
+        return(*msg);
+
+    resultLen = msgLen + count + 1;
+    result = (xmlChar *) xmlMallocAtomic(resultLen * sizeof(xmlChar));
+    if (result == NULL) {
+        /* Clear *msg to prevent format string vulnerabilities in
+           out-of-memory situations. */
+        xmlFree(*msg);
+        *msg = NULL;
+        xmlErrMemory(NULL, NULL);
+        return(NULL);
+    }
+
+    for (msgPtr = *msg, resultPtr = result; *msgPtr != '\0'; ++msgPtr, ++resultPtr) {
+        *resultPtr = *msgPtr;
+        if (*msgPtr == '%')
+            *(++resultPtr) = '%';
+    }
+    result[resultLen - 1] = '\0';
+
+    xmlFree(*msg);
+    *msg = result;
+
+    return *msg;
+}
+
 #define bottom_xmlstring
 #include "elfgcchack.h"