Import precedences are assigned in post-order over the import tree, so
sibling imports are distinct and every unit sits above its own
imports; apply-imports searches only the current template's
stylesheet's own import subtree per 5.6, reverting to the built-in
rule when that unit imports nothing; an included stylesheet's
declarations join the including unit at its precedence while its
imports join the import list; and include/import hrefs resolve against
the including stylesheet's URI. Included documents' roots stay
retained until their declarations are parsed (tree parents are weak,
so the in-scope xmlns chain could vanish mid-compile). Xalan baseline
159 -> 144 (reluri 11 -> 3, impincl 9 -> 2).
Same-name xsl:attribute-set declarations merge as ordered definitions
per 7.1.4, each expanding its used sets before its own attributes with
later definitions winning; xsl:copy carries the source element's
in-scope namespace nodes per 7.5; the namespace fixup lets a carried
attribute prefix shadow an inherited binding unless the element's own
name relies on it; the html method minimizes boolean attributes whose
value repeats their name; and external DTDs and entities in the
stylesheet or source resolve through the transform's document loader.
Four unit tests pin the behaviors. Xalan baseline 174 -> 159
(attribset 13 -> 4, copy 12 -> 7).
Raw-output marker resolution and 16.4 stripping run only when the
stylesheet mentions disable-output-escaping, so source text containing
U+E000/U+E001 survives every other transform untouched, and the text
method removes markers without unescaping content that was never
escaped. The pattern-matching function table is built once per
transform instead of per (template, node) membership test, and a dead
variable left in the numbering engine is gone. Eight focused unit
tests cover d-o-e (with the fragment rule and marker safety), CDATA
terminator splitting, simplified syntax, the html default method with
META injection, per-document key(), and attribute-start axes, so the
burn-down behaviors are CI-visible without the opt-in corpus.
