Let APT macro blocks end at the last brace on the line

doxia-modules/doxia-module-apt/src/main/java/org/apache/maven/doxia/module/apt/AptParser.java

@@ -2371,7 +2371,10 @@
             }
 
             final int start = text.indexOf('{');
-            final int end = text.indexOf('}');
+            // the macro block always ends with the closing brace, so look for the last one:
+            // parameter values may contain braces themselves (e.g. unresolved Velocity references
+            // such as ${project.build.directory} when the raw source of a *.apt.vm file is parsed)
+            final int end = text.lastIndexOf('}');
 
             String s = text.substring(start + 1, end);
 
@@ -2398,7 +2401,7 @@
 
             // getBasedir() does not work in multi-module builds, see DOXIA-373
             // the basedir should be injected from here, see DOXIA-224
             MacroRequest request = new MacroRequest(sourceContent, new AptParser(), parameters, getBasedir());
             try {
                 AptParser.this.executeMacro(macroId, request, sink);
             } catch (MacroExecutionException e) {

doxia-modules/doxia-module-apt/src/test/java/org/apache/maven/doxia/module/apt/AptParserTest.java

@@ -25,6 +25,8 @@
 import java.io.StringWriter;
 import java.io.Writer;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
 
 import org.apache.maven.doxia.parser.AbstractParser;
 import org.apache.maven.doxia.parser.AbstractParserTest;
@@ -75,6 +77,29 @@ void snippetMacro() throws Exception {
         assertTrue(macro.contains("<modelVersion\\>4.0.0\\</modelVersion\\>"));
     }
 
+    /**
+     * A macro parameter value may contain braces itself, for example an unresolved Velocity
+     * reference when the raw source of a {@code *.apt.vm} file is parsed. The macro block ends
+     * with the last brace on the line, not the first one.
+     */
+    @Test
+    void macroWithBracesInParameterValue() throws Exception {
+        Map<String, Object> parameters = new LinkedHashMap<>();
+
+        AbstractParser parser = createParser();
+        parser.setMacroExecutor((id, request, sink) -> {
+            assertEquals("snippet", id);
+            parameters.putAll(request.getParameters());
+        });
+
+        try (Reader reader = getTestReader("test/macro-braces-in-parameter")) {
+            parser.parse(reader, new SinkEventTestingSink());
+        }
+
+        assertEquals("superpom", parameters.get("id"));
+        assertEquals("${project.build.directory}/test-classes/pom-4.0.0.xml", parameters.get("file"));
+    }
+
     @Test
     void commentsBeforeTitle() throws Exception {
         String comments = parseFileToAptSink("test/comments");

doxia-modules/doxia-module-apt/src/test/resources/test/macro-braces-in-parameter.apt

@@ -0,0 +1,7 @@
+ -----
+ Braces in macro parameters
+ -----
+
+Braces in macro parameters
+
+%{snippet|id=superpom|file=${project.build.directory}/test-classes/pom-4.0.0.xml}