1 files changed, 33 insertions, 6 deletions
diff --git a/src/bg/ReportingCSP.js b/src/bg/ReportingCSP.js
index f8764e8..03926c2 100644
--- a/src/bg/ReportingCSP.js
+++ b/src/bg/ReportingCSP.js
@@ -1,6 +1,12 @@
 "use strict";
   
-function ReportingCSP(reportURI, reportGroup) { 
+function ReportingCSP(reportURI, reportGroup) {
+  const REPORT_TO = {
+    name: "Report-To",
+    value: JSON.stringify({ "url": reportURI,
+             "group": reportGroup,
+             "max-age": 10886400 }),
+  };
   return Object.assign(
     new CapsCSP(new NetCSP(
       `report-uri ${reportURI};`,
@@ -9,11 +15,32 @@ function ReportingCSP(reportURI, reportGroup) {
     {
       reportURI,
       reportGroup,
-      reportToHeader: {
-        name: "Report-To",
-        value: JSON.stringify({ "url": reportURI,
-                 "group": reportGroup,
-                 "max-age": 10886400 }),
+      patchHeaders(responseHeaders, capabilities) {
+        let header = null;
+        let hasReportTo = false;
+        for (let h of responseHeaders) {
+          if (this.isMine(h)) {
+            header = h;
+            h.value = this.inject(h.value, "");
+          } else if (h.name === REPORT_TO.name && h.value === REPORT_TO.value) {
+            hasReportTo = true;
+          }
+        }
+
+        let blocker = capabilities && this.buildFromCapabilities(capabilities);
+        if (blocker) {
+          if (!hasReportTo) {
+            responseHeaders.push(REPORT_TO);
+          }
+          if (header) {
+            header.value = this.inject(header.value, blocker);
+          } else {
+            header = this.asHeader(blocker);
+            responseHeaders.push(header);
+          }
+        }
+        
+        return header;
       }
     }
   );