android: prevent UnsatisfiedLinkError on Android <9

apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/AppCommon.android.kt

@@ -61,8 +61,11 @@ fun initHaskell() {
     }
   }
 
-  System.loadLibrary("app-lib")
-
+  try {
+    System.loadLibrary("app-lib")
+  } catch (e: UnsatisfiedLinkError) {
+    System.loadLibrary("apppatched-lib")
+  }
   s.acquire()
   pipeStdOutToSocket(socketName)
 

apps/multiplatform/common/src/commonMain/cpp/android/CMakeLists.txt

@@ -23,6 +23,15 @@ add_library( # Sets the name of the library.
     # Provides a relative path to your source file(s).
     simplex-api.c)
 
+add_library( # Sets the name of the library.
+    apppatched-lib
+
+    # Sets the library as a shared library.
+    SHARED
+
+    # Provides a relative path to your source file(s).
+    patch.c simplex-api.c)
+
 # Searches for a specified prebuilt library and stores the path as a
 # variable. Because CMake includes system libraries in the search path by
 # default, you only need to specify the name of the public NDK library
@@ -65,3 +74,13 @@ target_link_libraries( # Specifies the target library.
     # Links the target library to the log library
     # included in the NDK.
     ${log-lib})
+
+
+target_link_libraries( # Specifies the target library.
+    apppatched-lib
+
+    simplex support
+
+    # Links the target library to the log library
+    # included in the NDK.
+    ${log-lib})

apps/multiplatform/common/src/commonMain/cpp/android/patch.c

@@ -0,0 +1,6 @@
+#include <stdint.h>
+
+extern int getentropy(void* __buffer, size_t __buffer_size)
+{
+    return 1;
+}

apps/multiplatform/common/src/commonMain/cpp/android/simplex-api.c

@@ -19,6 +19,8 @@ extern void __strcat_chk_generic(void){};
 extern void __libc_globals(void){};
 extern void __rel_iplt_start(void){};
 
+int getentropy(void* __buffer, size_t __buffer_size);
+
 // Android 9 only, not 13
 extern void reallocarray(void){};
 
@@ -32,6 +34,8 @@ Java_chat_simplex_common_platform_CoreKt_pipeStdOutToSocket(JNIEnv *env, __unuse
 
 JNIEXPORT void JNICALL
 Java_chat_simplex_common_platform_CoreKt_initHS(__unused JNIEnv *env, __unused jclass clazz) {
+    //char tmp;
+    //__android_log_print(ANDROID_LOG_ERROR, "simplex", "entropy %d\n", getentropy(&tmp, sizeof(tmp)));
     hs_init(NULL, NULL);
     setLineBuffering();
 }