[libxml2] Introduce xmlPosixStrdup and update xmlMemStrdup

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 71462a600608f5263e3907eef8d685571abeb1b9
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Thu Nov 9 13:42:33 2017 +0100

    Introduce xmlPosixStrdup and update xmlMemStrdup
    
    Introduce xmlPosixStrdup, an internal strdup implementation matching the
    POSIX strdup type signature, and update xmlMemStrdup to use it.
    
    Thanks to Vlad Tsyrklevich for the initial patch.

 globals.c |   22 +++++++++++++++++-----
 1 files changed, 17 insertions(+), 5 deletions(-)
---
diff --git a/globals.c b/globals.c
index e351b03..20b4308 100644
--- a/globals.c
+++ b/globals.c
@@ -92,7 +92,7 @@ xmlStrdupFunc xmlMemStrdup = (xmlStrdupFunc) xmlMemoryStrdup;
  *
  * The variable holding the libxml free() implementation
  */
-xmlFreeFunc xmlFree = (xmlFreeFunc) free;
+xmlFreeFunc xmlFree = free;
 /**
  * xmlMalloc:
  * @size:  the size requested in bytes
@@ -101,7 +101,7 @@ xmlFreeFunc xmlFree = (xmlFreeFunc) free;
  *
  * Returns a pointer to the newly allocated block or NULL in case of error
  */
-xmlMallocFunc xmlMalloc = (xmlMallocFunc) malloc;
+xmlMallocFunc xmlMalloc = malloc;
 /**
  * xmlMallocAtomic:
  * @size:  the size requested in bytes
@@ -112,7 +112,7 @@ xmlMallocFunc xmlMalloc = (xmlMallocFunc) malloc;
  *
  * Returns a pointer to the newly allocated block or NULL in case of error
  */
-xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) malloc;
+xmlMallocFunc xmlMallocAtomic = malloc;
 /**
  * xmlRealloc:
  * @mem: an already allocated block of memory
@@ -122,7 +122,19 @@ xmlMallocFunc xmlMallocAtomic = (xmlMallocFunc) malloc;
  *
  * Returns a pointer to the newly reallocated block or NULL in case of error
  */
-xmlReallocFunc xmlRealloc = (xmlReallocFunc) realloc;
+xmlReallocFunc xmlRealloc = realloc;
+/**
+ * xmlPosixStrdup
+ * @cur:  the input char *
+ *
+ * a strdup implementation with a type signature matching POSIX
+ *
+ * Returns a new xmlChar * or NULL
+ */
+static char *
+xmlPosixStrdup(const char *cur) {
+    return((char*) xmlCharStrdup(cur));
+}
 /**
  * xmlMemStrdup:
  * @str: a zero terminated string
@@ -131,7 +143,7 @@ xmlReallocFunc xmlRealloc = (xmlReallocFunc) realloc;
  *
  * Returns the copy of the string or NULL in case of error
  */
-xmlStrdupFunc xmlMemStrdup = (xmlStrdupFunc) xmlStrdup;
+xmlStrdupFunc xmlMemStrdup = xmlPosixStrdup;
 #endif /* DEBUG_MEMORY_LOCATION || DEBUG_MEMORY */
 
 #include <libxml/threads.h>