Merge pull request #2705 from rajansingh10/myfeature

Fixing multi response header issue along with putting checks in http message parser.

Author: rajansingh10

src/System.Net.Http/src/System/Net/Http/Unix/CurlCallbacks.cs

@@ -23,6 +23,9 @@ namespace System.Net.Http
     internal partial class CurlHandler
     {
         private const string s_httpPrefix = "HTTP/";
+        private static readonly char[] s_newLineCharArray = new char[] { HttpRuleParser.CR, HttpRuleParser.LF };
+        private const char SpaceChar = ' ';
+        private const int StatusCodeLength = 3;
 
         private static Interop.libcurl.curl_readwrite_callback s_receiveHeadersCallback =
             (Interop.libcurl.curl_readwrite_callback) CurlReceiveHeadersCallback;
@@ -204,29 +207,88 @@ private static bool TryParseStatusLine(HttpResponseMessage response, string resp
                 return false;
             }
 
+            // Clear the header if status line is recieved again. This signifies that there are multiple response headers (like in redirection).
+            response.Headers.Clear();
+            
+            response.Content.Headers.Clear();        
+
+            int responseHeaderLength = responseHeader.Length;
+
             // Check if line begins with HTTP/1.1 or HTTP/1.0
             int prefixLength = s_httpPrefix.Length;
-            if ((responseHeader[prefixLength] == '1') && (responseHeader[prefixLength + 1] == '.'))
+            int versionIndex = prefixLength + 2;
+
+            if ((versionIndex < responseHeaderLength) && (responseHeader[prefixLength] == '1') && (responseHeader[prefixLength + 1] == '.'))
             {
-                if (responseHeader[prefixLength + 2] == '1')
+                if (responseHeader[versionIndex] == '1')
+                {
+                    response.Version = HttpVersion.Version11;
+                }
+                else if (responseHeader[versionIndex] == '0')
                 {
-                    response.Version = new Version(1, 1);
+                    response.Version = HttpVersion.Version10;
                 }
-                else if (responseHeader[prefixLength + 2] == '0')
+                else
                 {
-                    response.Version = new Version(1, 0);
+                    response.Version = new Version(0, 0);
                 }
             }
-
-            // Parse first 3 characters after a space as status code
+            else
+            {
+                response.Version = new Version(0, 0);
+            }
+         
             // TODO: Parsing errors are treated as fatal. Find right behaviour
-            int statusCodeLength = 3;
-            int codeIndex = responseHeader.IndexOf(' ') + 1;
-            string strStatusCode = responseHeader.Substring(codeIndex, statusCodeLength);
-            response.StatusCode = (HttpStatusCode)(int.Parse(strStatusCode));
+           
+            int spaceIndex = responseHeader.IndexOf(SpaceChar);
+
+            if (spaceIndex > -1)
+            {
+                int codeStartIndex = spaceIndex + 1;              
+                int statusCode = 0;
+
+                // Parse first 3 characters after a space as status code
+                if (TryParseStatusCode(responseHeader, codeStartIndex, out statusCode))
+                {
+                    response.StatusCode = (HttpStatusCode)statusCode;
+
+                    int codeEndIndex = codeStartIndex + StatusCodeLength;
+
+                    int reasonPhraseIndex = codeEndIndex + 1;
+
+                    if (reasonPhraseIndex < responseHeaderLength && responseHeader[codeEndIndex] == SpaceChar)
+                    {
+                        int newLineCharIndex = responseHeader.IndexOfAny(s_newLineCharArray, reasonPhraseIndex);
+                        int reasonPhraseEnd = newLineCharIndex >= 0 ? newLineCharIndex : responseHeaderLength;
+                        response.ReasonPhrase = responseHeader.Substring(reasonPhraseIndex, reasonPhraseEnd - reasonPhraseIndex);
+                    }
+                }               
+            }
+            
+            return true;
+        }
+
+        private static bool TryParseStatusCode(string responseHeader, int statusCodeStartIndex, out int statusCode)
+        {          
+            if (statusCodeStartIndex + StatusCodeLength > responseHeader.Length)
+            {
+                statusCode = 0;
+                return false;
+            }
+
+            char c100 = responseHeader[statusCodeStartIndex];
+            char c10 = responseHeader[statusCodeStartIndex + 1];
+            char c1 = responseHeader[statusCodeStartIndex + 2];
+
+            if (c100 < '0' || c100 > '9' ||
+                c10 < '0' || c10 > '9' ||
+                c1 < '0' || c1 > '9')
+            {
+                statusCode = 0;
+                return false;
+            }
 
-            // The remaining string after the space is the reason phrase
-            response.ReasonPhrase = responseHeader.Substring(codeIndex + statusCodeLength + 1);
+            statusCode =  (c100 - '0') * 100 +  (c10 - '0') * 10 +  (c1 - '0');
 
             return true;
         }