Index: gimp-texturize-2.1/src/graph.h
===================================================================
--- gimp-texturize-2.1.orig/src/graph.h	2005-04-08 09:03:45.000000000 -0300
+++ gimp-texturize-2.1/src/graph.h	2012-01-09 16:47:09.142045318 -0300
@@ -111,7 +111,7 @@
 	   function which will be called if an error occurs;
 	   an error message is passed to this function. If this
 	   argument is omitted, exit(1) will be called. */
-	Graph(void (*err_function)(char *) = NULL);
+	Graph(void (*err_function)(const char *) = NULL);
 
 	/* Destructor */
 	~Graph();
@@ -186,7 +186,7 @@
 	Block<arc>			*arc_block;
 	DBlock<nodeptr>		*nodeptr_block;
 
-	void	(*error_function)(char *);	/* this function is called if a error occurs,
+	void	(*error_function)(const char *);	/* this function is called if a error occurs,
 										   with a corresponding error message
 										   (or exit(1) is called if it's NULL) */
 
Index: gimp-texturize-2.1/src/block.h
===================================================================
--- gimp-texturize-2.1.orig/src/block.h	2005-04-08 09:03:45.000000000 -0300
+++ gimp-texturize-2.1/src/block.h	2012-01-09 16:48:47.197746395 -0300
@@ -105,7 +105,7 @@
 	   (optionally) the pointer to the function which
 	   will be called if allocation failed; the message
 	   passed to this function is "Not enough memory!" */
-	Block(int size, void (*err_function)(char *) = NULL) { first = last = NULL; block_size = size; error_function = err_function; }
+	Block(int size, void (*err_function)(const char *) = NULL) { first = last = NULL; block_size = size; error_function = err_function; }
 
 	/* Destructor. Deallocates all items added so far */
 	~Block() { while (first) { block *next = first -> next; delete first; first = next; } }
@@ -192,7 +192,7 @@
 	block	*scan_current_block;
 	Type	*scan_current_data;
 
-	void	(*error_function)(char *);
+	void	(*error_function)(const char *);
 };
 
 /***********************************************************************/
@@ -206,7 +206,7 @@
 	   (optionally) the pointer to the function which
 	   will be called if allocation failed; the message
 	   passed to this function is "Not enough memory!" */
-	DBlock(int size, void (*err_function)(char *) = NULL) { first = NULL; first_free = NULL; block_size = size; error_function = err_function; }
+	DBlock(int size, void (*err_function)(const char *) = NULL) { first = NULL; first_free = NULL; block_size = size; error_function = err_function; }
 
 	/* Destructor. Deallocates all items added so far */
 	~DBlock() { while (first) { block *next = first -> next; delete first; first = next; } }
@@ -260,7 +260,7 @@
 	block		*first;
 	block_item	*first_free;
 
-	void	(*error_function)(char *);
+	void	(*error_function)(const char *);
 };
 
 
Index: gimp-texturize-2.1/src/graph.cpp
===================================================================
--- gimp-texturize-2.1.orig/src/graph.cpp	2005-04-08 09:03:45.000000000 -0300
+++ gimp-texturize-2.1/src/graph.cpp	2012-01-09 16:49:16.432464864 -0300
@@ -4,7 +4,7 @@
 #include <stdio.h>
 #include "graph.h"
 
-Graph::Graph(void (*err_function)(char *))
+Graph::Graph(void (*err_function)(const char *))
 {
 	error_function = err_function;
 	node_block = new Block<node>(NODE_BLOCK_SIZE, error_function);
