CLOSES #455, CLOSES #487, CLOSES #501, CLOSES #540, CLOSES #585, CLOSES #591, CLOSES #593, CLOSES #595, CLOSES #597, CLOSES #599, CLOSES #600, CLOSES #606, CLOSES #607, CLOSES #610, CLOSES #613, CLOSES #616, CLOSES #620, CLOSES #626, CLOSES #632, CLOSES #633, CLOSES #647

mobile/android/love/src/jni/love/src/common/android.cpp

@@ -253,6 +253,41 @@ bool restartApp()
 	return result;
 }
 
+bool httpDownload(const char *url, const char *destPath, const char *userAgent, const char *accept)
+{
+	if (url == nullptr || destPath == nullptr)
+		return false;
+
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = env->FindClass("org/love2d/android/GameActivity");
+
+	// Old APK / new liblove skew: report "no transport" the same way a
+	// missing curl does, instead of aborting on a missing method (#597).
+	jmethodID method = env->GetStaticMethodID(activity, "httpDownload",
+		"(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Z");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return false;
+	}
+
+	jstring jurl = env->NewStringUTF(url);
+	jstring jdest = env->NewStringUTF(destPath);
+	jstring jua = env->NewStringUTF(userAgent != nullptr ? userAgent : "gen1recomp");
+	jstring jaccept = accept != nullptr ? env->NewStringUTF(accept) : nullptr;
+
+	jboolean result = env->CallStaticBooleanMethod(activity, method, jurl, jdest, jua, jaccept);
+
+	env->DeleteLocalRef(jurl);
+	env->DeleteLocalRef(jdest);
+	env->DeleteLocalRef(jua);
+	if (jaccept != nullptr)
+		env->DeleteLocalRef(jaccept);
+	env->DeleteLocalRef(activity);
+	return result;
+}
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/common/android.h

@@ -90,6 +90,14 @@ bool syncHealthSteps();
  **/
 bool restartApp();
 
+/**
+ * Blocking HTTPS GET into destPath (GameActivity.httpDownload). Android has
+ * no curl binary, so this is the transport src/core/HostShell.lua uses there
+ * for the mod index and mod updates (#597). userAgent / accept may be null.
+ * Returns whether a complete file was written.
+ **/
+bool httpDownload(const char *url, const char *destPath, const char *userAgent, const char *accept);
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/modules/system/System.cpp

@@ -230,6 +230,20 @@ bool System::restartApp() const
 #endif
 }
 
+bool System::httpDownload(const char *url, const char *destPath,
+	const char *userAgent, const char *accept) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::httpDownload(url, destPath, userAgent, accept);
+#else
+	LOVE_UNUSED(url);
+	LOVE_UNUSED(destPath);
+	LOVE_UNUSED(userAgent);
+	LOVE_UNUSED(accept);
+	return false;
+#endif
+}
+
 bool System::hasBackgroundMusic() const
 {
 #if defined(LOVE_ANDROID)

mobile/android/love/src/jni/love/src/modules/system/System.h

@@ -141,6 +141,14 @@ public:
 	 **/
 	virtual bool restartApp() const;
 
+	/**
+	 * Blocking HTTPS GET into an absolute host path (Android only; false
+	 * elsewhere). Android has no curl, which is what every other platform
+	 * fetches the mod index with (#597).
+	 **/
+	virtual bool httpDownload(const char *url, const char *destPath,
+		const char *userAgent = nullptr, const char *accept = nullptr) const;
+
 	/**
 	 * Gets if the user is playing music on background.
 	 * Throws an exception on unsupported platforms.

mobile/android/love/src/jni/love/src/modules/system/wrap_System.cpp

@@ -123,6 +123,16 @@ int w_restartApp(lua_State *L)
 	return 1;
 }
 
+int w_httpDownload(lua_State *L)
+{
+	const char *url = luaL_checkstring(L, 1);
+	const char *dest = luaL_checkstring(L, 2);
+	const char *ua = luaL_optstring(L, 3, nullptr);
+	const char *accept = luaL_optstring(L, 4, nullptr);
+	luax_pushboolean(L, instance()->httpDownload(url, dest, ua, accept));
+	return 1;
+}
+
 int w_hasBackgroundMusic(lua_State *L)
 {
 	lua_pushboolean(L, instance()->hasBackgroundMusic());
@@ -142,6 +152,7 @@ static const luaL_Reg functions[] =
 	{ "createFile", w_createFile },
 	{ "syncHealthSteps", w_syncHealthSteps },
 	{ "restartApp", w_restartApp },
+	{ "httpDownload", w_httpDownload },
 	{ "hasBackgroundMusic", w_hasBackgroundMusic },
 	{ 0, 0 }
 };