Expand step does not correct set is_root flag on blocks

[xzyfer]

This will be an issue when trying to fix #1651.

a {
  @at-root (without: media) {
    b: c
  }
}

Before expand

Block 0x7fecb8c04310 (0@[0:0]-[62:0]) [root] 0
 Ruleset 0x7fecb8d03750 (0@[4:0]-[8:1]) [indent: 0] [root]
 >Selector_List 0x7fecb8d037f0 (0@[4:0]-[4:1]) [@media:0x0] - - -
 > Complex_Selector 0x7fecb8d03a20 (0@[4:0]-[4:1]) [weight:100] [@media:0x0] - - - --  <>
 >  Compound_Selector 0x7fecb8d038b0 (0@[4:0]-[4:0]) [weight:100] [@media:0x0] - - - <>
 >   Type_Selector 0x7fecb8d03970 (0@[4:0]-[4:1]) <<a>> - <>

After expand

Block 0x7fecb8d17520 (0@[0:0]-[62:0]) [root] 0
 Ruleset 0x7fecb8d181c0 (0@[4:0]-[8:1]) [indent: 0]
 >Selector_List 0x7fecb8d17600 (0@[4:0]-[4:1]) [@media:0x0] - - -
 > Complex_Selector 0x7fecb8d03a20 (0@[4:0]-[4:1]) [weight:100] [@media:0x0] - - - --  <>
 >  Compound_Selector 0x7fecb8d038b0 (0@[4:0]-[4:0]) [weight:100] [@media:0x0] - - - <>
 >   Type_Selector 0x7fecb8d03970 (0@[4:0]-[4:1]) <<a>> - <>

[mgreter]

IMO we should refactor to make Has_Block directly inherit from Block (basically replacing class AST_XY : public Has_Block to class AST_XY : public Block. Reason for this is that we currently cannot push At_Root_Blocks etc. to the import_stack. Therefore we loose some information when later querying the current block context. But I guess this will introduce difficulties for cssize.

[xzyfer]

IMO we should refactor to make Has_Block directly inherit from Block

The Ruby implementation does what you're suggesting AFAIK.

But I guess this will introduce difficulties for cssize.

I don't think this will be an issue. The cssize is a direct line-for-line port from the Ruby implementation.

[mgreter]

@xzyfer: waiting for your parser refactor before I'll start tackling this. Probably needs another major refactoring, since my first naive try to do this was shorty stopped by some complications in cssize!