Readding callee check. (#634)

* Render blocks in the parent context and assure a block is passed to
templates that use @partial-block

* Fixed checkstyle errors.

* Readded lazy evaluation.

* Readded inline partial evaluation.

* Added option to turn lazy partial evaluation on and off

* Fix checkstyle errors.

* Revert to original whitespaces

* Revert to original whitespace

* Added tests for lazy partial block evaluation

* Renamed lazy to pre and inverted booleans.

* Fix for issue 588

Author: nyon

handlebars/src/main/java/com/github/jknack/handlebars/internal/Partial.java

@@ -23,6 +23,7 @@
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.Writer;
+import java.util.Arrays;
 import java.nio.charset.Charset;
 import java.util.Collections;
 import java.util.HashMap;
@@ -123,6 +124,16 @@ protected void merge(final Context context, final Writer writer)
       Map<String, Template> inlineTemplates = partials.getLast();
       Template callee = context.data(Context.CALLEE);
 
+      final boolean pathIsPartialBlock = "@partial-block".equals(path);
+      final Template lastPartialBlock = inlineTemplates.get("@partial-block");
+      final boolean parentIsNotLastPartialBlock = !isCalleeOf(callee, lastPartialBlock);
+
+      if (pathIsPartialBlock && parentIsNotLastPartialBlock) {
+        throw new IllegalArgumentException(
+                callee + " does not provide a @partial-block for " + this
+        );
+      }
+
       if (this.partial != null) {
         if (handlebars.preEvaluatePartialBlocks()) {
           this.partial.apply(context);
@@ -197,6 +208,23 @@ protected void merge(final Context context, final Writer writer)
     }
   }
 
+  /**
+   * @param callee parent template of the currently traversed template
+   * @param partialBlock partial block candidate
+   * @return returns if callee and partialBlock are the same
+   */
+  private boolean isCalleeOf(final Template callee, final Template partialBlock) {
+    if (callee == null || partialBlock == null) {
+      return false;
+    }
+
+    if (!callee.filename().equalsIgnoreCase(partialBlock.filename())) {
+      return false;
+    }
+
+    return Arrays.equals(callee.position(), partialBlock.position());
+  }
+
   /**
    * True, if the file was already processed.
    *

handlebars/src/main/java/com/github/jknack/handlebars/internal/PartialBlockForwardingTemplate.java

@@ -66,7 +66,7 @@ public PartialBlockForwardingTemplate(
         this.block = block;
         this.parentPartialBlock = parentPartialBlock;
         this.callee = callee;
-        this.filename(block.filename());
+        this.filename(parent.filename());
         this.position(parent.position()[0], parent.position()[1]);
     }