I did it backwards, I needed to use the explicit context from the block, not the inline partial.

js/test_cases/explicit_context_setting/README.md

@@ -31,7 +31,7 @@ Explicitly setting a context on an inline partial does not work, but it does not
 
 Explicitly setting a context on a block does work.
 
-The explicit context for inline partials is evaluated in the context for that template file containing the block, not the inline partial (so, whatever the context is when we invoke the partial containing the block).
+The explicit context for blocks is evaluated in the context for that template file containing the block, not the inline partial (so, whatever the context is when we invoke the partial containing the block).
 
 References
 ----------

src/renderer/inline_partial_tree.rs

@@ -1,23 +1,18 @@
 use crate::parser::Body;
 use crate::parser::DustTag;
 use crate::parser::Template;
-use crate::parser::{Path, TemplateElement};
+use crate::parser::TemplateElement;
 use std::collections::HashMap;
 
-pub struct InlinePartialTreeValue<'a> {
-    explicit_context: &'a Option<Path<'a>>,
-    body: &'a Option<Body<'a>>,
-}
-
 pub struct InlinePartialTreeElement<'a> {
     parent: Option<&'a InlinePartialTreeElement<'a>>,
-    blocks: HashMap<&'a str, InlinePartialTreeValue<'a>>,
+    blocks: HashMap<&'a str, &'a Option<Body<'a>>>,
 }
 
 impl<'a> InlinePartialTreeElement<'a> {
     pub fn new(
         parent: Option<&'a InlinePartialTreeElement<'a>>,
-        blocks: HashMap<&'a str, InlinePartialTreeValue<'a>>,
+        blocks: HashMap<&'a str, &'a Option<Body<'a>>>,
     ) -> InlinePartialTreeElement<'a> {
         InlinePartialTreeElement {
             parent: parent,
@@ -25,40 +20,21 @@ impl<'a> InlinePartialTreeElement<'a> {
         }
     }
 
-    fn get_value(&self, name: &str) -> Option<&InlinePartialTreeValue<'a>> {
+    pub fn get_block(&self, name: &str) -> Option<&'a Option<Body<'a>>> {
         match self.blocks.get(name) {
             None => match self.parent {
                 None => None,
-                Some(parent_tree_element) => parent_tree_element.get_value(name),
+                Some(parent_tree_element) => parent_tree_element.get_block(name),
             },
             Some(interior) => Some(interior),
         }
     }
-
-    /// Recursively get the body of a block by name
-    ///
-    /// Returning a double-option because there is a functional
-    /// difference between not finding the block and not having a
-    /// body.
-    pub fn get_block(&self, name: &str) -> Option<&'a Option<Body<'a>>> {
-        self.get_value(name).map(|interior| interior.body)
-    }
-
-    /// Recursively get the explicit from the inline partial by name
-    ///
-    /// Returning a double-option because there is a functional
-    /// difference between not finding the block and not having a
-    /// body.
-    pub fn get_explicit_context(&self, name: &str) -> Option<&Option<Path<'a>>> {
-        self.get_value(name)
-            .map(|interior| interior.explicit_context)
-    }
 }
 
 pub fn extract_inline_partials<'a>(
     template: &'a Template<'a>,
-) -> HashMap<&'a str, InlinePartialTreeValue<'a>> {
-    let mut blocks: HashMap<&'a str, InlinePartialTreeValue<'a>> = HashMap::new();
+) -> HashMap<&'a str, &'a Option<Body<'a>>> {
+    let mut blocks: HashMap<&'a str, &'a Option<Body<'a>>> = HashMap::new();
 
     extract_inline_partials_from_body(&mut blocks, &template.contents);
 
@@ -66,7 +42,7 @@ pub fn extract_inline_partials<'a>(
 }
 
 fn extract_inline_partials_from_body<'a, 'b>(
-    blocks: &'b mut HashMap<&'a str, InlinePartialTreeValue<'a>>,
+    blocks: &'b mut HashMap<&'a str, &'a Option<Body<'a>>>,
     body: &'a Body<'a>,
 ) {
     for elem in &body.elements {
@@ -81,7 +57,7 @@ fn extract_inline_partials_from_body<'a, 'b>(
 }
 
 fn extract_inline_partials_from_tag<'a, 'b>(
-    blocks: &'b mut HashMap<&'a str, InlinePartialTreeValue<'a>>,
+    blocks: &'b mut HashMap<&'a str, &'a Option<Body<'a>>>,
     tag: &'a DustTag,
 ) {
     match tag {
@@ -121,13 +97,7 @@ fn extract_inline_partials_from_tag<'a, 'b>(
         }
         DustTag::DTPartial(..) => (),
         DustTag::DTInlinePartial(named_block) => {
-            blocks.insert(
-                &named_block.name,
-                InlinePartialTreeValue {
-                    explicit_context: &named_block.explicit_context,
-                    body: &named_block.contents,
-                },
-            );
+            blocks.insert(&named_block.name, &named_block.contents);
         }
         DustTag::DTBlock(..) => (),
         DustTag::DTHelperEquals(parameterized_block) => {

src/renderer/renderer.rs

@@ -343,27 +343,21 @@ impl<'a> DustRenderer<'a> {
                 return Ok("".to_owned());
             }
             DustTag::DTBlock(named_block) => {
-                let new_breadcrumbs = blocks
-                    .blocks
-                    .get_explicit_context(named_block.name)
-                    .map(|explicit_context| {
-                        Self::new_breadcrumbs(
-                            breadcrumbs,
-                            blocks.breadcrumbs,
-                            None,
-                            explicit_context,
-                            None,
-                        )
-                    })
-                    .flatten();
+                let new_breadcrumbs = Self::new_breadcrumbs(
+                    breadcrumbs,
+                    blocks.breadcrumbs,
+                    None,
+                    &named_block.explicit_context,
+                    None,
+                );
                 return match blocks.blocks.get_block(named_block.name) {
                     None => self.render_maybe_body(
                         &named_block.contents,
                         new_breadcrumbs.as_ref().unwrap_or(breadcrumbs),
                         blocks,
                     ),
-                    Some(interior) => self.render_maybe_body(
-                        interior,
+                    Some(inline_partial) => self.render_maybe_body(
+                        inline_partial,
                         new_breadcrumbs.as_ref().unwrap_or(breadcrumbs),
                         blocks,
                     ),