#openttdcoop

diff --git a/nml/actions/real_sprite.py b/nml/actions/real_sprite.py
--- a/nml/actions/real_sprite.py
+++ b/nml/actions/real_sprite.py
@@ -160,9 +160,12 @@ class RealSprite(object):
 
     @ivar flags: Cropping/warning flags.
     @type flags: L{expression.ConstantNumeric}
+
+    @ivar poslist: Position of creation of the sprite, if available.
+    @type poslist: C{list} of L{Position}
     """
 
-    def __init__(self, param_list = None, label = None):
+    def __init__(self, param_list = None, label = None, poslist = None):
         self.param_list = param_list
         self.label = label
         self.is_empty = False
@@ -170,6 +173,10 @@ class RealSprite(object):
         self.ypos = None
         self.xsize = None
         self.ysize = None
+        if poslist is None:
+            self.poslist = []
+        else:
+            self.poslist = poslist
 
     def debug_print(self, indentation):
         generic.print_dbg(indentation, 'Real sprite, parameters:')
@@ -182,8 +189,8 @@ class RealSprite(object):
             labels[self.label.value] = 0
         return labels, 1
 
-    def expand(self, default_file, default_mask_file, id_dict):
-        return [parse_real_sprite(self, default_file, default_mask_file, id_dict)]
+    def expand(self, default_file, default_mask_file, poslist, id_dict):
+        return [parse_real_sprite(self, default_file, default_mask_file, poslist, id_dict)]
 
     def check_sprite_size(self):
         generic.check_range(self.xpos.value,  0, 0x7fffFFFF,   "Real sprite paramater 'xpos'", self.xpos.pos)
@@ -249,6 +256,13 @@ class RealSprite(object):
         return (rgb_file, rgb_rect, mask_file, mask_rect, do_crop)
 
 class SpriteAction(base_action.BaseAction):
+    """
+    @ivar sprite_num: Number of the sprite, or C{None} if not decided yet.
+    @type sprite_num: C{int} or C{None}
+
+    @ivar last: Whether this sprite action is the last of a series.
+    @type last: C{bool}
+    """
     def __init__(self):
         self.sprite_num = None
         self.last = False
@@ -275,9 +289,13 @@ class RealSpriteAction(SpriteAction):
         if self.last: file.newline()
 
 class RecolourSprite(object):
-    def __init__(self, mapping, label = None):
+    def __init__(self, mapping, label = None, poslist = None):
         self.mapping = mapping
         self.label = label
+        if poslist is None:
+            self.poslist = []
+        else:
+            self.poslist = poslist
 
     def debug_print(self, indentation):
         generic.print_dbg(indentation, 'Recolour sprite, mapping:')
@@ -290,7 +308,7 @@ class RecolourSprite(object):
             labels[self.label.value] = 0
         return labels, 1
 
-    def expand(self, default_file, default_mask_file, id_dict):
+    def expand(self, default_file, default_mask_file, poslist, id_dict):
         # create new struct, needed for template expansion
         new_mapping = []
         for old_assignment in self.mapping:
@@ -299,7 +317,7 @@ class RecolourSprite(object):
             to_min_value = old_assignment.value.min.reduce_constant([id_dict])
             to_max_value = None if old_assignment.value.max is None else old_assignment.value.max.reduce_constant([id_dict])
             new_mapping.append(assignment.Assignment(assignment.Range(from_min_value, from_max_value), assignment.Range(to_min_value, to_max_value), old_assignment.pos))
-        return [RecolourSprite(new_mapping)]
+        return [RecolourSprite(new_mapping, poslist = poslist)]
 
     def __str__(self):
         ret = "" if self.label is None else str(self.label) + ": "
@@ -372,7 +390,7 @@ class TemplateUsage(object):
             labels[self.label.value] = 0
         return labels, offset
 
-    def expand(self, default_file, default_mask_file, parameters):
+    def expand(self, default_file, default_mask_file, poslist, parameters):
         if self.name.value not in sprite_template_map:
             raise generic.ScriptError("Encountered unknown template identifier: " + self.name.value, self.name.pos)
         template = sprite_template_map[self.name.value]
@@ -385,13 +403,13 @@ class TemplateUsage(object):
                 raise generic.ScriptError("Template parameters should be compile-time constants", param.pos)
             param_dict[template.param_list[i].value] = param.value
 
-        return parse_sprite_list(template.sprite_list, default_file, default_mask_file, param_dict)
+        return parse_sprite_list(template.sprite_list, default_file, default_mask_file, poslist + [self.pos], param_dict)
 
     def __str__(self):
         return "{}({})".format(self.name, ", ".join(str(param) for param in self.param_list))
 
 
-def parse_real_sprite(sprite, default_file, default_mask_file, id_dict):
+def parse_real_sprite(sprite, default_file, default_mask_file, poslist, id_dict):
     # check the number of parameters
     num_param = len(sprite.param_list)
     if num_param == 0:
@@ -401,7 +419,7 @@ def parse_real_sprite(sprite, default_fi
         raise generic.ScriptError("Invalid number of arguments for real sprite. Expected 2..9.", sprite.param_list[0].pos)
 
     # create new sprite struct, needed for template expansion
-    new_sprite = RealSprite()
+    new_sprite = RealSprite(poslist = poslist + sprite.poslist)
 
     param_offset = 0
 
@@ -474,10 +492,10 @@ def parse_real_sprite(sprite, default_fi
 
 sprite_template_map = {}
 
-def parse_sprite_list(sprite_list, default_file, default_mask_file, parameters = {}):
+def parse_sprite_list(sprite_list, default_file, default_mask_file, poslist, parameters = {}):
     real_sprite_list = []
     for sprite in sprite_list:
-        real_sprite_list.extend(sprite.expand(default_file, default_mask_file, parameters))
+        real_sprite_list.extend(sprite.expand(default_file, default_mask_file, poslist, parameters))
     return real_sprite_list
 
 def parse_sprite_data(sprite_container):
@@ -493,8 +511,8 @@ def parse_sprite_data(sprite_container):
     first = True
 
     for sprite_data in all_sprite_data:
-        sprite_list, default_file, default_mask_file, zoom_level, bit_depth = sprite_data
-        new_sprite_list = parse_sprite_list(sprite_list, default_file, default_mask_file)
+        sprite_list, default_file, default_mask_file, pos, zoom_level, bit_depth = sprite_data
+        new_sprite_list = parse_sprite_list(sprite_list, default_file, default_mask_file, [pos])
         if not first and len(new_sprite_list) != len(action_list):
             msg = "Expected {:d} alternative sprites for {} '{}', got {:d}."
             msg = msg.format(len(action_list), sprite_container.block_type, sprite_container.block_name.value, len(new_sprite_list))
diff --git a/nml/ast/sprite_container.py b/nml/ast/sprite_container.py
--- a/nml/ast/sprite_container.py
+++ b/nml/ast/sprite_container.py
@@ -28,7 +28,7 @@ class SpriteContainer(object):
     @type block_name: L{Identifier}, or C{None} if N/A
 
     @ivar sprite_data: Mapping of (zoom level, bit-depth) to (sprite list, default file)
-    @type sprite_data: C{dict} that maps (C{tuple} of (C{int}, C{int})) to (C{tuple} of (C{list} of (L{RealSprite}, L{RecolourSprite} or L{TemplateUsage}), L{StringLiteral} or C{None}))
+    @type sprite_data: C{dict} that maps (C{tuple} of (C{int}, C{int})) to (C{tuple} of (C{list} of (L{RealSprite}, L{RecolourSprite} or L{TemplateUsage}), L{StringLiteral} or C{None}, L{Position}))
     """
     sprite_blocks = {}
 
@@ -50,14 +50,17 @@ class SpriteContainer(object):
                    "level / bit depth combination. This data will be overridden.")
             msg = msg.format(self.block_type, self.block_name.value)
             generic.print_warning(msg, pos)
-        self.sprite_data[key] = (sprite_list, default_file, default_mask_file)
+        self.sprite_data[key] = (sprite_list, default_file, default_mask_file, pos)
 
     def get_all_sprite_data(self):
         """
-        Get all sprite data as a list of 5-tuples (sprite_list, default_file, default_mask_file, zoom_level, bit_depth)
-        Sorting makes sure that the order is consistent, and that the normal zoom, 8bpp sprites appear first
+        Get all sprite data.
+        Sorting makes sure that the order is consistent, and that the normal zoom, 8bpp sprites appear first.
+
+        @return: List of 6-tuples (sprite_list, default_file, default_mask_file, position, zoom_level, bit_depth).
+        @rtype:  C{list} of C{tuple} of (C{list} of (L{RealSprite}, L{RecolourSprite} or L{TemplateUsage}), L{StringLiteral} or C{None}, L{Position}, C{int}, C{int})
         """
-        return [(self.sprite_data[key][0], self.sprite_data[key][1], self.sprite_data[key][2], key[0], key[1]) for key in sorted(self.sprite_data)]
+        return [val + key for key, val in sorted(self.sprite_data.items())]
 
     @classmethod
     def resolve_sprite_block(cls, block_name):
diff --git a/nml/generic.py b/nml/generic.py
--- a/nml/generic.py
+++ b/nml/generic.py
@@ -139,8 +139,10 @@ class ImageFilePosition(Position):
     """
     Generic (not position-dependant) error with an image file
     """
-    def __init__(self, filename):
-        Position.__init__(self, filename, [])
+    def __init__(self, filename, pos = None):
+        poslist = []
+        if pos is not None: poslist.append(pos)
+        Position.__init__(self, filename, poslist)
 
     def __str__(self):
         return 'Image file "{}"'.format(self.filename)
@@ -181,8 +183,8 @@ class RangeError(ScriptError):
         ScriptError.__init__(self, name + " out of range " + str(min_value) + ".." + str(max_value) + ", encountered " + str(value), pos)
 
 class ImageError(ScriptError):
-    def __init__(self, value, filename):
-        ScriptError.__init__(self, value, ImageFilePosition(filename))
+    def __init__(self, value, filename, pos = None):
+        ScriptError.__init__(self, value, ImageFilePosition(filename, pos))
 
 class OnlyOnceError(ScriptError):
     """
diff --git a/nml/parser.py b/nml/parser.py
--- a/nml/parser.py
+++ b/nml/parser.py
@@ -451,9 +451,9 @@ class NMLParser(object):
         '''real_sprite : LBRACKET expression_list RBRACKET
                        | ID COLON LBRACKET expression_list RBRACKET'''
         if len(t) == 4:
-            t[0] = real_sprite.RealSprite(t[2])
+            t[0] = real_sprite.RealSprite(param_list = t[2], poslist = [t.lineno(1)])
         else:
-            t[0] = real_sprite.RealSprite(t[4], t[1])
+            t[0] = real_sprite.RealSprite(param_list = t[4], label = t[1], poslist = [t.lineno(1)])
 
     def p_recolour_assignment_list(self, t):
         '''recolour_assignment_list :
diff --git a/nml/spriteencoder.py b/nml/spriteencoder.py
--- a/nml/spriteencoder.py
+++ b/nml/spriteencoder.py
@@ -263,14 +263,16 @@ class SpriteEncoder(object):
         if filename_32bpp is not None:
             im = self.open_image_file(filename_32bpp.value)
             if im.mode not in ("RGB", "RGBA"):
-                raise generic.ImageError("32bpp image is not a full colour RGB(A) image.", filename_32bpp.value)
+                pos = build_position(sprite_info.poslist)
+                raise generic.ImageError("32bpp image is not a full colour RGB(A) image.", filename_32bpp.value, pos)
             info_byte |= INFO_RGB
             if im.mode == "RGBA":
                 info_byte |= INFO_ALPHA
 
             (im_width, im_height) = im.size
             if x < 0 or y < 0 or x + size_x > im_width or y + size_y > im_height:
-                raise generic.ScriptError("Read beyond bounds of image file '{}'".format(filename_32bpp.value), filename_32bpp.pos)
+                pos = build_position(sprite_info.poslist)
+                raise generic.ScriptError("Read beyond bounds of image file '{}'".format(filename_32bpp.value), pos)
             sprite = im.crop((x, y, x + size_x, y + size_y))
             rgb_sprite_data = sprite.tostring()
 
@@ -281,13 +283,15 @@ class SpriteEncoder(object):
         if filename_8bpp is not None:
             mask_im = self.open_image_file(filename_8bpp.value)
             if mask_im.mode != "P":
-                raise generic.ImageError("8bpp image does not have a palette", filename_8bpp.value)
+                pos = build_position(sprite_info.poslist)
+                raise generic.ImageError("8bpp image does not have a palette", filename_8bpp.value, pos)
             im_mask_pal = palette.validate_palette(mask_im, filename_8bpp.value)
             info_byte |= INFO_PAL
 
             (im_width, im_height) = mask_im.size
             if mask_x < 0 or mask_y < 0 or mask_x + size_x > im_width or mask_y + size_y > im_height:
-                raise generic.ScriptError("Read beyond bounds of image file '{}'".format(filename_8bpp.value), filename_8bpp.pos)
+                pos = build_position(sprite_info.poslist)
+                raise generic.ScriptError("Read beyond bounds of image file '{}'".format(filename_8bpp.value), pos)
             mask_sprite = mask_im.crop((mask_x, mask_y, mask_x + size_x, mask_y + size_y))
 
             mask_sprite_data = self.palconvert(mask_sprite.tostring(), im_mask_pal)
@@ -497,3 +501,21 @@ class SpriteEncoder(object):
         else:
             return sprite_str
 
+def build_position(poslist):
+    """
+    Construct a L{Position} object that expands to positions in the template instantiation stack.
+
+    @param poslist: Sequence of positions to report. First entry is the innermost template,
+                    last entry is the nml statement that started it all.
+    @type  poslist: C{list} of L{Position}
+
+    @return: Position to attach to an error.
+    @rtype:  L{Position}
+    """
+    if poslist is None or len(poslist) == 0:
+        return None
+    if len(poslist) == 1:
+        return poslist[0]
+    pos = poslist[-1]
+    pos.includes = pos.includes + poslist[:-1]
+    return pos

Mark as private