diff --git a/dom/base/NodeInfo.cpp b/dom/base/NodeInfo.cpp
index 0a66d4deff9cb..6aa73e2a853a5 100644
--- a/dom/base/NodeInfo.cpp
+++ b/dom/base/NodeInfo.cpp
@@ -152,6 +152,10 @@ void NodeInfo::GetPrefix(nsAString& aPrefix) const {
 
 void NodeInfo::GetNamespaceURI(nsAString& aNameSpaceURI) const {
   if (mInner.mNamespaceID > 0) {
+    if (!nsNameSpaceManager::GetInstance()) {
+      SetDOMStringToNull(aNameSpaceURI);
+      return;
+    }
     nsresult rv = nsNameSpaceManager::GetInstance()->GetNameSpaceURI(
         mInner.mNamespaceID, aNameSpaceURI);
     // How can we possibly end up with a bogus namespace ID here?
diff --git a/js/moz.configure b/js/moz.configure
index cbcaf38f01c9d..b52afe7c75230 100644
--- a/js/moz.configure
+++ b/js/moz.configure
@@ -494,6 +494,15 @@ set_config("JS_JITSPEW", depends_if("--enable-jitspew")(lambda _: True))
 set_define("JS_STRUCTURED_SPEW", depends_if("--enable-jitspew")(lambda _: True))
 set_config("JS_STRUCTURED_SPEW", depends_if("--enable-jitspew")(lambda _: True))
 
+option(
+    "--enable-taintspew",
+    default=False,
+    help="{Enable|Disable} the taint flow spew variable",
+)
+
+# Also enable the structured spewer for tainting
+set_define("JS_STRUCTURED_SPEW", depends_if("--enable-taintspew")(lambda _: True))
+set_config("JS_STRUCTURED_SPEW", depends_if("--enable-taintspew")(lambda _: True))
 
 @depends("--enable-jit", "--enable-jitspew", simulator, target, moz_debug)
 def jit_disasm_arm(jit_enabled, spew, simulator, target, debug):
diff --git a/js/src/builtin/String.cpp b/js/src/builtin/String.cpp
index a841a52f05d22..98f1e7aabefbc 100644
--- a/js/src/builtin/String.cpp
+++ b/js/src/builtin/String.cpp
@@ -123,6 +123,8 @@ static bool str_encodeURI(JSContext* cx, unsigned argc, Value* vp);
 
 static bool str_encodeURI_Component(JSContext* cx, unsigned argc, Value* vp);
 
+static bool str_foxhound(JSContext* cx, unsigned argc, Value* vp);
+
 /*
  * Global string methods
  */
@@ -723,7 +725,7 @@ static const JSFunctionSpec string_functions[] = {
     JS_FN("encodeURI", str_encodeURI, 1, JSPROP_RESOLVING),
     JS_FN("decodeURIComponent", str_decodeURI_Component, 1, JSPROP_RESOLVING),
     JS_FN("encodeURIComponent", str_encodeURI_Component, 1, JSPROP_RESOLVING),
-
+    JS_FN("foxhound", str_foxhound, 1, JSPROP_RESOLVING),
     JS_FS_END,
 };
 
@@ -5325,6 +5327,21 @@ JSString* js::EncodeURI(JSContext* cx, const char* chars, size_t length) {
   return sb.finishString();
 }
 
+static bool str_foxhound(JSContext* cx, unsigned argc, Value* vp) {
+  AutoJSMethodProfilerEntry pseudoFrame(cx, "foxhound");
+  CallArgs args = CallArgsFromVp(argc, vp);
+  // This will also do conversions from numbers to strings
+  Rooted<JSLinearString*> str(cx, ArgToLinearString(cx, args, 0));
+  if (!str) {
+    return false;
+  }
+
+  MaybeSpewMessage(cx, str);
+
+  args.rval().setUndefined();
+  return true;
+}
+
 static bool FlatStringMatchHelper(JSContext* cx, HandleString str,
                                   HandleString pattern, bool* isFlat,
                                   int32_t* match) {
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index c4fa087b08251..8e02208c3ecf6 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -5072,6 +5072,8 @@ JS_ReportTaintSink(JSContext* cx, JS::HandleString str, const char* sink, JS::Ha
   RootedValue rval(cx);
   JS_CallFunction(cx, nullptr, report, arguments, &rval);
   MOZ_ASSERT(!cx->isExceptionPending());
+
+  MaybeSpewStringTaint(cx, str);
 }
 
 JS_PUBLIC_API bool JS::FinishIncrementalEncoding(JSContext* cx,
diff --git a/js/src/jstaint.cpp b/js/src/jstaint.cpp
index 22a4da241f96a..d28f707cfbf5f 100644
--- a/js/src/jstaint.cpp
+++ b/js/src/jstaint.cpp
@@ -17,6 +17,7 @@
 #include "js/ErrorReport.h"
 #include "js/UniquePtr.h"
 #include "vm/FrameIter.h"
+#include "vm/JSAtomUtils.h"
 #include "vm/JSContext.h"
 #include "vm/JSFunction.h"
 #include "vm/StringType.h"
@@ -371,6 +372,83 @@ void JS::MarkTaintedFunctionArguments(JSContext* cx, JSFunction* function, const
   }
 }
 
+void JS::MaybeSpewStringTaint(JSContext* cx, JSString* str) {
+#ifdef JS_STRUCTURED_SPEW
+  if (!str || !str->taint()) {
+    return;
+  }
+
+  AutoStructuredSpewer spew(cx, SpewChannel::TaintFlowSpewer, cx->currentScript());
+  if (spew) {
+    JSLinearString* linear = str->ensureLinear(cx);
+    if (linear) {
+      spew->property("str", linear);
+    } else {
+      spew->property("str", "Non-linear String!");
+    }
+
+    spew->beginListProperty("taint");
+    for (const TaintRange& range : str->taint()) {
+      spew->beginObject();
+      spew->property("begin", range.begin());
+      spew->property("end", range.end());
+
+      spew->beginListProperty("flow");
+      for (TaintNode& node : range.flow()) {
+        const TaintOperation& op = node.operation();
+        spew->beginObject();
+        spew->property("operation", op.name());
+        spew->boolProperty("builtin", op.is_native());
+        spew->boolProperty("source", op.isSource());
+
+        const TaintLocation& loc = op.location();
+        spew->beginObjectProperty("location");
+        spew->property("filename", loc.filename().c_str(), loc.filename().size());
+        spew->property("line", loc.line());
+        spew->property("pos", loc.pos());
+        spew->property("scriptline", loc.scriptStartLine());
+        spew->property("scripthash", JS::convertDigestToHexString(loc.scriptHash()).c_str());
+        spew->endObject(); // Location
+
+        spew->beginListProperty("arguments");
+        for (auto& arg : op.arguments()) {
+          spew->string(arg.c_str(), arg.size());
+        }
+        spew->endList();
+
+        spew->endObject(); // Operation
+      }
+      spew->endList(); // flow
+      spew->endObject(); // range
+    }
+    spew->endList();
+
+  }
+#endif
+}
+
+void JS::MaybeSpewMessage(JSContext* cx, JSString* str) {
+  // First print message to stderr
+  SEprinter p;
+  p.put("!!! foxhound() called with message: ");
+  p.putString(cx, str);
+  p.put("\n");
+  p.flush();
+
+#ifdef JS_STRUCTURED_SPEW
+  // Spew to file if enabled
+  AutoStructuredSpewer spew(cx, SpewChannel::TaintFlowSpewer, cx->currentScript());
+  if (spew) {
+    JSLinearString* linear = str->ensureLinear(cx);
+    if (linear) {
+      spew->property("foxhound", linear);
+    } else {
+      spew->property("foxhound", "Non-linear String!");
+    }
+  }
+#endif
+}
+
 // Print a message to stdout.
 void JS::TaintFoxReport(JSContext* cx, const char* msg)
 {
diff --git a/js/src/jstaint.h b/js/src/jstaint.h
index 767f48c302850..b604c7530d486 100644
--- a/js/src/jstaint.h
+++ b/js/src/jstaint.h
@@ -85,6 +85,11 @@ TaintOperation TaintOperationFromContext(JSContext* cx, const char* name, bool i
 // This is mainly useful for tracing tainted arguments through the code.
 void MarkTaintedFunctionArguments(JSContext* cx, JSFunction* function, const JS::CallArgs& args);
 
+// Write the taint report to file
+void MaybeSpewStringTaint(JSContext* cx, JSString* str);
+// Write a message to the file
+void MaybeSpewMessage(JSContext* cx, JSString* str);
+
 // Print a message to stdout.
 void TaintFoxReport(JSContext* cx, const char* msg);
 
diff --git a/js/src/util/StructuredSpewer.cpp b/js/src/util/StructuredSpewer.cpp
index 72f483c6b5472..f2fe82ca0f6d0 100644
--- a/js/src/util/StructuredSpewer.cpp
+++ b/js/src/util/StructuredSpewer.cpp
@@ -31,7 +31,7 @@ const StructuredSpewer::NameArray StructuredSpewer::names_ = {
 #    if defined(_WIN32)
 #      define DEFAULT_SPEW_DIRECTORY "."
 #    elif defined(__ANDROID__)
-#      define DEFAULT_SPEW_DIRECTORY "/data/local/tmp"
+#      define DEFAULT_SPEW_DIRECTORY "/sdcard/Download"
 #    else
 #      define DEFAULT_SPEW_DIRECTORY "."
 #    endif
diff --git a/js/src/util/StructuredSpewer.h b/js/src/util/StructuredSpewer.h
index 613ef65b59ae7..ae7c34deb20c0 100644
--- a/js/src/util/StructuredSpewer.h
+++ b/js/src/util/StructuredSpewer.h
@@ -73,7 +73,8 @@ namespace js {
 
 #  define STRUCTURED_CHANNEL_LIST(_) \
     _(BaselineICStats)               \
-    _(CacheIRHealthReport)
+    _(CacheIRHealthReport)           \
+    _(TaintFlowSpewer)
 
 // Structured spew channels
 enum class SpewChannel {
@@ -125,9 +126,13 @@ class StructuredSpewer {
         spewingEnabled_(0),
         json_(mozilla::Nothing()),
         selectedChannel_() {
+#if defined(__ANDROID__)
+      parseSpewFlags("TaintFlowSpewer,AtStartup");
+#else
     if (getenv("SPEW")) {
       parseSpewFlags(getenv("SPEW"));
     }
+#endif
   }
 
   ~StructuredSpewer() {
diff --git a/js/src/vm/JSONPrinter.cpp b/js/src/vm/JSONPrinter.cpp
index 5b5183d9fb7c5..cac6a93a5014b 100644
--- a/js/src/vm/JSONPrinter.cpp
+++ b/js/src/vm/JSONPrinter.cpp
@@ -143,6 +143,18 @@ void JSONPrinter::property(const char* name, const char* value) {
   endStringProperty();
 }
 
+void JSONPrinter::property(const char* name, const char16_t* value, size_t length) {
+  beginStringProperty(name);
+  JSONString(out_, value, length);
+  endStringProperty();
+}
+
+void JSONPrinter::string(const char16_t* value, size_t length) {
+  JSONString(beginString(), value, length);
+  endString();
+  first_ = false;
+}
+
 void JSONPrinter::formatProperty(const char* name, const char* format, ...) {
   va_list ap;
   va_start(ap, format);
diff --git a/js/src/vm/JSONPrinter.h b/js/src/vm/JSONPrinter.h
index b90696a2b448f..06a16e4c2b662 100644
--- a/js/src/vm/JSONPrinter.h
+++ b/js/src/vm/JSONPrinter.h
@@ -49,6 +49,7 @@ class JSONPrinter {
 
   void property(const char* name, JSLinearString* value);
   void property(const char* name, const char* value);
+  void property(const char* name, const char16_t* value, size_t length);
   void property(const char* name, int32_t value);
   void property(const char* name, uint32_t value);
   void property(const char* name, int64_t value);
@@ -60,6 +61,8 @@ class JSONPrinter {
   void property(const char* name, size_t value);
 #endif
 
+  void string(const char16_t* value, size_t length);
+
   void formatProperty(const char* name, const char* format, ...)
       MOZ_FORMAT_PRINTF(3, 4);
   void formatProperty(const char* name, const char* format, va_list ap);