do not use a global ifblock stack

Using a global ifblock stack for all parsed ifblock objects causes
problems when doing sub-parsing in objects taking other objects as
parameters, because the possibly non-empty stack at startup leads to
false alarm when checking for stack emptiness after parsing the objects.

Use a void ** as the object to pass around, so callers don't need to
know struct ifblock_stack_obj.

src/conky.c

@@ -1573,7 +1573,7 @@ static const char *dev_name(const char *path)
 
 /* construct_text_object() creates a new text_object */
 static struct text_object *construct_text_object(const char *s,
-		const char *arg, long line, char allow_threaded)
+		const char *arg, long line, char allow_threaded, void **ifblock_opaque)
 {
 	// struct text_object *obj = new_text_object();
 	struct text_object *obj = new_text_object_internal();
@@ -1775,9 +1775,9 @@ static struct text_object *construct_text_object(const char *s,
 			obj->data.ifblock.s = 0;
 		} else
 			obj->data.ifblock.s = strndup(arg, text_buffer_size);
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(if_gw, 0)
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(ioscheduler, 0)
 		if (!arg) {
 			CRIT_ERR("get_ioscheduler needs an argument (e.g. hda)");
@@ -1966,9 +1966,9 @@ static struct text_object *construct_text_object(const char *s,
 		obj->data.net = get_net_stat(buf);
 		free(buf);
 	END OBJ(else, 0)
-		obj_be_ifblock_else(obj);
+		obj_be_ifblock_else(ifblock_opaque, obj);
 	END OBJ(endif, 0)
-		obj_be_ifblock_endif(obj);
+		obj_be_ifblock_endif(ifblock_opaque, obj);
 	END OBJ(image, 0)
 		obj->data.s = strndup(arg ? arg : "", text_buffer_size);
 #ifdef HAVE_POPEN
@@ -2518,7 +2518,7 @@ static struct text_object *construct_text_object(const char *s,
 		} else {
 			obj->data.ifblock.s = strndup(arg, text_buffer_size);
 		}
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(if_match, 0)
 		if (!arg) {
 			ERR("if_match needs arguments");
@@ -2526,7 +2526,7 @@ static struct text_object *construct_text_object(const char *s,
 		} else {
 			obj->data.ifblock.s = strndup(arg, text_buffer_size);
 		}
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(if_existing, 0)
 		if (!arg) {
 			ERR("if_existing needs an argument or two");
@@ -2545,7 +2545,7 @@ static struct text_object *construct_text_object(const char *s,
 			}
 		}
 		DBGP("if_existing: '%s' '%s'", obj->data.ifblock.s, obj->data.ifblock.str);
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(if_mounted, 0)
 		if (!arg) {
 			ERR("if_mounted needs an argument");
@@ -2553,7 +2553,7 @@ static struct text_object *construct_text_object(const char *s,
 		} else {
 			obj->data.ifblock.s = strndup(arg, text_buffer_size);
 		}
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(if_running, 0)
 		if (arg) {
 			char buf[256];
@@ -2564,7 +2564,7 @@ static struct text_object *construct_text_object(const char *s,
 			ERR("if_running needs an argument");
 			obj->data.ifblock.s = 0;
 		}
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(kernel, 0)
 	END OBJ(machine, 0)
 	END OBJ(mails, 0)
@@ -2847,7 +2847,7 @@ static struct text_object *construct_text_object(const char *s,
 			obj->data.ifblock.s = 0;
 		} else
 			obj->data.ifblock.s = strndup(arg, text_buffer_size);
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 	END OBJ(smapi_bat_perc, 0)
 		if (arg)
 			obj->data.s = strndup(arg, text_buffer_size);
@@ -2919,7 +2919,7 @@ static struct text_object *construct_text_object(const char *s,
 		mpd_set_maxlen(mpd_smart);
 		init_mpd();
 	END OBJ(if_mpd_playing, INFO_MPD)
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 		init_mpd();
 #undef mpd_set_maxlen
 #endif /* MPD */
@@ -2958,7 +2958,7 @@ static struct text_object *construct_text_object(const char *s,
 	END OBJ(xmms2_playlist, INFO_XMMS2)
 	END OBJ(xmms2_timesplayed, INFO_XMMS2)
 	END OBJ(if_xmms2_connected, INFO_XMMS2)
-		obj_be_ifblock_if(obj);
+		obj_be_ifblock_if(ifblock_opaque, obj);
 #endif
 #ifdef AUDACIOUS
 	END OBJ(audacious_status, INFO_AUDACIOUS)
@@ -3288,6 +3288,7 @@ static int extract_variable_text_internal(struct text_object *retval, const char
 	struct text_object *obj;
 	char *p, *s, *orig_p;
 	long line;
+	void *ifblock_opaque = NULL;
 
 	p = strndup(const_p, max_user_text - 1);
 	while (text_contains_templates(p)) {
@@ -3390,7 +3391,9 @@ static int extract_variable_text_internal(struct text_object *retval, const char
 						tmp_p++;
 					}
 
-					obj = construct_text_object(buf, arg, line, allow_threaded);
+					obj = construct_text_object(buf, arg,
+							line, allow_threaded,
+							&ifblock_opaque);
 					if (obj != NULL) {
 						append_object(retval, obj);
 					}
@@ -3410,7 +3413,7 @@ static int extract_variable_text_internal(struct text_object *retval, const char
 		append_object(retval, obj);
 	}
 
-	if (!ifblock_stack_empty()) {
+	if (!ifblock_stack_empty(&ifblock_opaque)) {
 		ERR("one or more $endif's are missing");
 	}
 

src/text_object.c

@@ -85,12 +85,6 @@ struct ifblock_stack_obj {
 	struct ifblock_stack_obj *next;
 };
 
-/* top of the internal ifblock stack
- * initially contains only one "object", i.e. a NULL pointer
- * indicating the end of the stack.
- */
-static struct ifblock_stack_obj *ifblock_stack_top = NULL;
-
 /* push an ifblock object onto the stack
  * in fact, this does a lot more:
  * - IFBLOCK_IF is just pushed onto the stack
@@ -100,37 +94,38 @@ static struct ifblock_stack_obj *ifblock_stack_top = NULL;
  *   object in the stack and then triggers stack popping of
  *   any optional IFBLOCK_ELSE along with it's IFBLOCK_IF
  */
-static int push_ifblock(struct text_object *obj, enum ifblock_type type)
+static int push_ifblock(struct ifblock_stack_obj **ifblock_stack_top,
+                        struct text_object *obj, enum ifblock_type type)
 {
 	struct ifblock_stack_obj *stackobj;
 
 	switch (type) {
 		case IFBLOCK_ENDIF:
-			if (!ifblock_stack_top)
+			if (!(*ifblock_stack_top))
 				CRIT_ERR("got an endif without matching if");
-			ifblock_stack_top->obj->data.ifblock.next = obj;
+			(*ifblock_stack_top)->obj->data.ifblock.next = obj;
 			/* if there's some else in between, remove and free it */
-			if (ifblock_stack_top->type == IFBLOCK_ELSE) {
+			if ((*ifblock_stack_top)->type == IFBLOCK_ELSE) {
-				stackobj = ifblock_stack_top;
+				stackobj = *ifblock_stack_top;
-				ifblock_stack_top = stackobj->next;
+				*ifblock_stack_top = stackobj->next;
 				free(stackobj);
 			}
 			/* finally remove and free the if object */
-			stackobj = ifblock_stack_top;
+			stackobj = *ifblock_stack_top;
-			ifblock_stack_top = stackobj->next;
+			*ifblock_stack_top = stackobj->next;
 			free(stackobj);
 			break;
 		case IFBLOCK_ELSE:
-			if (!ifblock_stack_top)
+			if (!(*ifblock_stack_top))
 				CRIT_ERR("got an else without matching if");
-			ifblock_stack_top->obj->data.ifblock.next = obj;
+			(*ifblock_stack_top)->obj->data.ifblock.next = obj;
 			/* fall through */
 		case IFBLOCK_IF:
 			stackobj = malloc(sizeof(struct ifblock_stack_obj));
 			stackobj->type = type;
 			stackobj->obj = obj;
-			stackobj->next = ifblock_stack_top;
+			stackobj->next = *ifblock_stack_top;
-			ifblock_stack_top = stackobj;
+			*ifblock_stack_top = stackobj;
 			break;
 		default:
 			CRIT_ERR("push_ifblock() missuse detected!");
@@ -140,23 +135,23 @@ static int push_ifblock(struct text_object *obj, enum ifblock_type type)
 
 /* public functions for client use */
 
-int obj_be_ifblock_if(struct text_object *obj)
+int obj_be_ifblock_if(void **opaque, struct text_object *obj)
 {
-	return push_ifblock(obj, IFBLOCK_IF);
+	return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_IF);
 }
-int obj_be_ifblock_else(struct text_object *obj)
+int obj_be_ifblock_else(void **opaque, struct text_object *obj)
 {
-	return push_ifblock(obj, IFBLOCK_ELSE);
+	return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ELSE);
 }
-int obj_be_ifblock_endif(struct text_object *obj)
+int obj_be_ifblock_endif(void **opaque, struct text_object *obj)
 {
-	return push_ifblock(obj, IFBLOCK_ENDIF);
+	return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ENDIF);
 }
 
 /* check if ifblock stack is empty
  * if so, return true (!= 0)
  */
-int ifblock_stack_empty(void)
+int ifblock_stack_empty(void **opaque)
 {
-	return ifblock_stack_top == NULL;
+	return *opaque == NULL;
 }

src/text_object.h

@@ -487,10 +487,15 @@ struct text_object {
 /* text object list helpers */
 int append_object(struct text_object *root, struct text_object *obj);
 
-/* ifblock helpers */
+/* ifblock helpers
-int obj_be_ifblock_if(struct text_object *);
+ *
-int obj_be_ifblock_else(struct text_object *);
+ * Opaque is a pointer to the address of the ifblock stack's top object.
-int obj_be_ifblock_endif(struct text_object *);
+ * Calling clients should pass the address of a defined void pointer which
-int ifblock_stack_empty(void);
+ * was initialised to NULL (empty stack).
+ * */
+int obj_be_ifblock_if(void **opaque, struct text_object *);
+int obj_be_ifblock_else(void **opaque, struct text_object *);
+int obj_be_ifblock_endif(void **opaque, struct text_object *);
+int ifblock_stack_empty(void **opaque);
 
 #endif /* _TEXT_OBJECT_H */