Fix some bugs with trying to access uninitialized variables.

miniaudio.h

 /*
 Audio playback and capture library. Choice of public domain or MIT-0. See license statements at the end of this file.
-miniaudio - v0.10.26 - 2020-11-24
+miniaudio - v0.10.27 - TBD
 
 David Reid - mackron@gmail.com
 
@@ -1447,7 +1447,7 @@ extern "C" {
 
 #define MA_VERSION_MAJOR    0
 #define MA_VERSION_MINOR    10
-#define MA_VERSION_REVISION 26
+#define MA_VERSION_REVISION 27
 #define MA_VERSION_STRING   MA_XSTRINGIFY(MA_VERSION_MAJOR) "." MA_XSTRINGIFY(MA_VERSION_MINOR) "." MA_XSTRINGIFY(MA_VERSION_REVISION)
 
 #if defined(_MSC_VER) && !defined(__clang__)
@@ -42869,6 +42869,18 @@ MA_API ma_result ma_data_source_get_data_format(ma_data_source* pDataSource, ma_
     ma_uint32 sampleRate;
     ma_data_source_callbacks* pCallbacks = (ma_data_source_callbacks*)pDataSource;
 
+    if (pFormat != NULL) {
+        *pFormat = ma_format_unknown;
+    }
+
+    if (pChannels != NULL) {
+        *pChannels = 0;
+    }
+
+    if (pSampleRate != NULL) {
+        *pSampleRate = 0;
+    }
+
     if (pCallbacks == NULL || pCallbacks->onGetDataFormat == NULL) {
         return MA_INVALID_ARGS;
     }
@@ -64249,6 +64261,9 @@ The following miscellaneous changes have also been made.
 /*
 REVISION HISTORY
 ================
+v0.10.27 - TBD
+  - Fix some bugs with trying to access uninitialized variables.
+
 v0.10.26 - 2020-11-24
   - WASAPI: Fix a bug where the exclusive mode format may not be retrieved correctly due to accessing freed memory.
   - Fix a bug with ma_waveform where glitching occurs after changing frequency.

research/miniaudio_engine.h

@@ -3621,11 +3621,15 @@ static ma_result ma_rb_data_source_init(ma_rb* pRB, ma_format format, ma_uint32
         return MA_INVALID_ARGS;
     }
 
+    MA_ZERO_OBJECT(pDataSource);    /* For safety. */
+
     pDataSource->ds.onRead          = NULL;
     pDataSource->ds.onSeek          = NULL;  /* We can't really seek in a ring buffer - there's no notion of a beginning and an end in a ring buffer. */
     pDataSource->ds.onMap           = ma_rb_data_source__on_map;
     pDataSource->ds.onUnmap         = ma_rb_data_source__on_unmap;
     pDataSource->ds.onGetDataFormat = ma_rb_data_source__on_get_format;
+    pDataSource->ds.onGetCursor     = NULL;
+    pDataSource->ds.onGetLength     = NULL;
     pDataSource->pRB                = pRB;
     pDataSource->format             = format;
     pDataSource->channels           = channels;
@@ -6149,6 +6153,14 @@ MA_API ma_result ma_resource_manager_data_stream_get_data_format(ma_resource_man
     /* We cannot be using the data source after it's been uninitialized. */
     MA_ASSERT(pDataStream->result != MA_UNAVAILABLE);
 
+    if (pFormat != NULL) {
+        *pFormat = ma_format_unknown;
+    }
+
+    if (pChannels != NULL) {
+        *pChannels = 0;
+    }
+
     if (pDataStream == NULL) {
         return MA_INVALID_ARGS;
     }