android: allow stdout/stderr capture using extra field on intent

This allows launching the Panda apk from termux and getting command-line output back to termux.

dtool/src/prc/androidLogStream.cxx

@@ -92,6 +92,7 @@ overflow(int ch) {
  */
 void AndroidLogStream::AndroidLogStreamBuf::
 write_char(char c) {
+  nout.put(c);
   if (c == '\n') {
     // Write a line to the log file.
     __android_log_write(_priority, _tag.c_str(), _data.c_str());

dtool/src/prc/notify.cxx

@@ -335,9 +335,8 @@ assert_failure(const char *expression, int line,
 
 #ifdef ANDROID
   __android_log_assert("assert", "Panda3D", "Assertion failed: %s", message.c_str());
-#else
-  nout << "Assertion failed: " << message << "\n";
 #endif
+  nout << "Assertion failed: " << message << "\n";
 
   // This is redefined here, shadowing the defining in config_prc.h, so we can
   // guarantee it has already been constructed.

dtool/src/prc/notifyCategory.cxx

@@ -64,7 +64,11 @@ out(NotifySeverity severity, bool prefix) const {
     // logging system.  We use a special type of stream that redirects it to
     // Android's log system.
     if (prefix) {
-      return AndroidLogStream::out(severity) << *this << ": ";
+      if (severity == NS_info) {
+        return AndroidLogStream::out(severity) << *this << ": ";
+      } else {
+        return AndroidLogStream::out(severity) << *this << "(" << severity << "): ";
+      }
     } else {
       return AndroidLogStream::out(severity);
     }

panda/src/android/PandaActivity.java

@@ -61,6 +61,11 @@ public class PandaActivity extends NativeActivity {
         return path;
     }
 
+    public String getIntentOutputPath() {
+        Intent intent = getIntent();
+        return intent.getStringExtra("org.panda3d.OUTPUT_PATH");
+    }
+
     public String getCacheDirString() {
         return getCacheDir().toString();
     }

panda/src/android/android_main.cxx

@@ -158,6 +158,28 @@ void android_main(struct android_app* app) {
     }
   }
 
+  // Were we given an optional location to write the stdout/stderr streams?
+  methodID = env->GetMethodID(activity_class, "getIntentOutputPath", "()Ljava/lang/String;");
+  jstring joutput_path = (jstring) env->CallObjectMethod(activity->clazz, methodID);
+  if (joutput_path != nullptr) {
+    const char *output_path = env->GetStringUTFChars(joutput_path, nullptr);
+
+    if (output_path != nullptr && output_path[0] != 0) {
+      int fd = open(output_path, O_CREAT | O_TRUNC | O_WRONLY);
+      if (fd != -1) {
+        android_cat.info()
+          << "Writing standard output to file " << output_path << "\n";
+
+        dup2(fd, 1);
+        dup2(fd, 2);
+      } else {
+        android_cat.error()
+          << "Failed to open output path " << output_path << "\n";
+      }
+      env->ReleaseStringUTFChars(joutput_path, output_path);
+    }
+  }
+
   // Create bogus argc and argv for calling the main function.
   const char *argv[] = {"pview", nullptr, nullptr};
   int argc = 1;

panda/src/express/virtualFileMountAndroidAsset.cxx

@@ -78,7 +78,7 @@ is_regular_file(const Filename &file) const {
   AAsset* asset;
   asset = AAssetManager_open(_asset_mgr, file.c_str(), AASSET_MODE_UNKNOWN);
 
-  express_cat.error() << "is_regular_file " << file << " - " << asset << "\n";
+  //express_cat.error() << "is_regular_file " << file << " - " << asset << "\n";
 
   if (asset == NULL) {
     return false;