fix(filters): scope source filters per compilation unit

src/main/java/org/perlonjava/core/Configuration.java

@@ -33,22 +33,22 @@ public final class Configuration {
      * Automatically populated by Gradle/Maven during build.
      * DO NOT EDIT MANUALLY - this value is replaced at build time.
      */
-    public static final String gitCommitId = "d7eacf972";
+    public static final String gitCommitId = "82e5e452d";
 
     /**
      * Git commit date of the build (ISO format: YYYY-MM-DD).
      * Automatically populated by Gradle/Maven during build.
      * DO NOT EDIT MANUALLY - this value is replaced at build time.
      */
-    public static final String gitCommitDate = "2026-04-28";
+    public static final String gitCommitDate = "2026-04-29";
 
     /**
      * Build timestamp in Perl 5 "Compiled at" format (e.g., "Apr  7 2026 11:20:00").
      * Automatically populated by Gradle during build.
      * Parsed by App::perlbrew and other tools via: perl -V | grep "Compiled at"
      * DO NOT EDIT MANUALLY - this value is replaced at build time.
      */
-    public static final String buildTimestamp = "Apr 28 2026 21:49:56";
+    public static final String buildTimestamp = "Apr 29 2026 09:31:10";
 
     // Prevent instantiation
     private Configuration() {

src/main/java/org/perlonjava/runtime/operators/ModuleOperators.java

@@ -711,7 +711,14 @@ else if (code == null) {
         // Notify B::Hooks::EndOfScope that we're starting to load a file
         // This enables on_scope_end callbacks to know which file they belong to
         BHooksEndOfScope.beginFileLoad(parsedArgs.fileName);
-
+
+        // Source filters installed in the caller's file must not leak into
+        // the file being required/do'd. Save the outer filter state and start
+        // with a clean state for this compilation unit; restore on the way out.
+        org.perlonjava.runtime.perlmodule.FilterUtilCall.FilterStateSnapshot
+                filterSnapshot = org.perlonjava.runtime.perlmodule.FilterUtilCall
+                        .saveAndResetFilterState();
+
         try {
             featureManager = new FeatureFlags();
 
@@ -755,6 +762,11 @@ else if (code == null) {
             // Restore the caller's hints hash
             hintHash.elements.clear();
             hintHash.elements.putAll(savedHintHash);
+
+            // Restore the caller's source-filter state (filters installed in
+            // the required file must not leak back to the caller).
+            org.perlonjava.runtime.perlmodule.FilterUtilCall
+                    .restoreFilterState(filterSnapshot);
         }
 
         // Return result based on context

src/main/java/org/perlonjava/runtime/perlmodule/FilterUtilCall.java

@@ -468,6 +468,52 @@ public static void clearFilters() {
         context.currentLine = 0;
     }
 
+    /**
+     * Snapshot of filter state (stack + "installed during use" flag).
+     * Source filters are scoped to the file/compilation unit in which
+     * they were installed; when we begin parsing a new file (e.g. via
+     * {@code require}/{@code do}), we save the outer state, start with
+     * a clean state, and restore on the way out.
+     */
+    public static class FilterStateSnapshot {
+        final RuntimeList filterStack;
+        final boolean installedDuringUse;
+
+        FilterStateSnapshot(RuntimeList filterStack, boolean installedDuringUse) {
+            this.filterStack = filterStack;
+            this.installedDuringUse = installedDuringUse;
+        }
+    }
+
+    /**
+     * Save the current filter state and reset to a clean state.
+     * Call this before compiling a new file (require/do); pair with
+     * {@link #restoreFilterState(FilterStateSnapshot)}.
+     */
+    public static FilterStateSnapshot saveAndResetFilterState() {
+        FilterContext context = filterContext.get();
+        FilterStateSnapshot snapshot =
+                new FilterStateSnapshot(context.filterStack, filterInstalledDuringUse.get());
+        context.filterStack = new RuntimeList();
+        context.sourceLines = null;
+        context.currentLine = 0;
+        filterInstalledDuringUse.set(false);
+        return snapshot;
+    }
+
+    /**
+     * Restore filter state previously saved by
+     * {@link #saveAndResetFilterState()}.
+     */
+    public static void restoreFilterState(FilterStateSnapshot snapshot) {
+        if (snapshot == null) return;
+        FilterContext context = filterContext.get();
+        context.filterStack = snapshot.filterStack;
+        context.sourceLines = null;
+        context.currentLine = 0;
+        filterInstalledDuringUse.set(snapshot.installedDuringUse);
+    }
+
     /**
      * Context for managing active source filters.
      */