[dia] [warningectomy] format string is not a string literal

[Hans Breuer <hans src gnome org>]

commit 980f70c22321d31c10b6c68fae0931cba5ec2a60
Author: Hans Breuer <hans breuer org>
Date:   Fri Oct 3 21:30:20 2014 +0200

    [warningectomy] format string is not a string literal
    
    Now also fix dia_assert_true() declaration and use.
    
    debug.c:39:15: warning: format string is not a string literal [-Wformat-nonliteral]
        g_vprintf(format, args);
                  ^~~~~~
    
    And followup warnings of the fix:
    
    object.c:1109:49: warning: more '%' conversions than data arguments [-Wformat]
                        "%s: Object %p has illegal type name %p (%s)\n",
                                                                 ~^
    object.c:1118:45: warning: format specifies type 'char *' but the argument has
          type 'const DiaObject *' (aka 'const struct _DiaObject *') [-Wformat]
                          "%s: Object %p has null handles\n", obj);
                           ~~                                 ^~~
    object.c:1118:22: warning: more '%' conversions than data arguments [-Wformat]
                          "%s: Object %p has null handles\n", obj);
                                      ~^

 lib/debug.c  |    3 ++-
 lib/debug.h  |    3 ++-
 lib/object.c |    4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/lib/debug.c b/lib/debug.c
index 3c8a962..348069b 100644
--- a/lib/debug.c
+++ b/lib/debug.c
@@ -32,7 +32,8 @@
  * @return val
  */
 gboolean
-dia_assert_true(gboolean val, gchar *format, ...) {
+dia_assert_true(gboolean val, const gchar *format, ...)
+{
   va_list args;
   if (!val) {
     va_start(args, format);
diff --git a/lib/debug.h b/lib/debug.h
index 205b3e1..bacc982 100644
--- a/lib/debug.h
+++ b/lib/debug.h
@@ -25,7 +25,8 @@
 
 #include <stdio.h>
 #include <stdarg.h>
+#include <glib.h>
 
-gboolean dia_assert_true(gboolean val, gchar *format, ...);
+gboolean dia_assert_true(gboolean val, const gchar *format, ...) G_GNUC_PRINTF(2,3);
 
 #endif
diff --git a/lib/object.c b/lib/object.c
index e9107f9..7a7ac10 100644
--- a/lib/object.c
+++ b/lib/object.c
@@ -1106,7 +1106,7 @@ dia_object_sanity_check(const DiaObject *obj, const gchar *msg) {
   if (obj != NULL) {
     dia_assert_true(obj->type->name != NULL &&
                    g_utf8_validate(obj->type->name, -1, NULL),
-                   "%s: Object %p has illegal type name %p (%s)\n",
+                   "%s: Object %p has illegal type name '%s'\n",
                    msg, obj, obj->type->name);
     /* Check the position vs. the bounding box */
     /* Check the handles */
@@ -1115,7 +1115,7 @@ dia_object_sanity_check(const DiaObject *obj, const gchar *msg) {
                    msg, obj,  obj->num_handles);
     if (obj->num_handles != 0) {
       dia_assert_true(obj->handles != NULL,
-                     "%s: Object %p has null handles\n", obj);
+                     "%s: Object %p has null handles\n", msg, obj);
     }
     for (i = 0; i < obj->num_handles; i++) {
       Handle *h = obj->handles[i];