Fixed an issue where the request stream might not be seekable

Author: niemyjski

src/Platforms/Exceptionless.AspNetCore/RequestInfoCollector.cs

@@ -43,11 +43,15 @@ public static RequestInfo Collect(HttpContext context, IEnumerable<string> exclu
             } else if (context.Request.ContentLength.HasValue && context.Request.ContentLength.Value > 0) {
                 if (context.Request.ContentLength.Value < 1024 * 50) {
                     try {
-                        if (context.Request.Body.Position > 0)
+                        if (context.Request.Body.CanSeek && context.Request.Body.Position > 0)
                             context.Request.Body.Position = 0;
 
-                        using (var inputStream = new StreamReader(context.Request.Body))
-                            info.PostData = inputStream.ReadToEnd();
+                        if (context.Request.Body.Position == 0) {
+                            using (var inputStream = new StreamReader(context.Request.Body))
+                                info.PostData = inputStream.ReadToEnd();
+                        } else {
+                            info.PostData = "Unable to get POST data: The stream could not be reset.";
+                        }
                     } catch (Exception ex) {
                         info.PostData = "Error retrieving POST data: " + ex.Message;
                     }

src/Platforms/Exceptionless.Web/RequestInfoCollector.cs

@@ -52,11 +52,15 @@ public static RequestInfo Collect(HttpContextBase context, ExceptionlessConfigur
             } else if (context.Request.ContentLength > 0) {
                 if (context.Request.ContentLength < 1024 * 50) {
                     try {
-                        if (context.Request.InputStream.Position > 0)
+                        if (context.Request.InputStream.CanSeek && context.Request.InputStream.Position > 0)
                             context.Request.InputStream.Position = 0;
 
-                        using (var inputStream = new StreamReader(context.Request.InputStream))
-                            info.PostData = inputStream.ReadToEnd();
+                        if (context.Request.InputStream.Position == 0) {
+                            using (var inputStream = new StreamReader(context.Request.InputStream))
+                                info.PostData = inputStream.ReadToEnd();
+                        } else {
+                            info.PostData = "Unable to get POST data: The stream could not be reset.";
+                        }
                     } catch (Exception ex) {
                         info.PostData = "Error retrieving POST data: " + ex.Message;
                     }