[MNG-6975] Wagon-HTTP, set content-type when determinable from file extension

wagon-providers/pom.xml

@@ -78,4 +78,5 @@ under the License.
       <scope>test</scope>
     </dependency>
   </dependencies>
+
 </project>

wagon-providers/wagon-http-shared/src/main/java/org/apache/maven/wagon/shared/http/AbstractHttpClientWagon.java

@@ -91,6 +91,7 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.RandomAccessFile;
+import java.net.URLConnection;
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
@@ -152,6 +153,58 @@ private WagonHttpEntity( final InputStream stream, final Resource resource, fina
             this.length = resource == null ? -1 : resource.getContentLength();
 
             this.wagon = wagon;
+
+            // if the autoset content flag is SET and the content type is blank
+            // then try to determine what the content type is and set it
+            if ( AUTOSET_CONTENT_TYPE && getContentType() == null )
+            {
+                try
+                {
+                    autosetContentType();
+                }
+                catch ( IOException ioX )
+                {
+                    if ( AUTOSET_CONTENT_TYPE_FATAL )
+                    {
+                        throw new TransferFailedException(
+                                "Failed to determine content type, "
+                                + " unset 'maven.wagon.http.autocontenttype.fatal' to allow continued processing",
+                                ioX );
+                    }
+                }
+            }
+        }
+
+        /**
+         * Try to determine the content type and set the content-type header if successful.
+         *
+         * if the content-type has not been set then
+         * if the (AUTOSET_CONTENT_TYPE) option flag is TRUE
+         * and
+         * the content is coming from a file and the content type is determinable from the file extension
+         * or
+         * the content is coming from a stream and the content type is determinable from the stream
+         *     (guessContentTypeFromStream will return null if the InputStream does not support mark())
+         * then determine and set the content type
+         * Note: the content-type will never be set to null or an empty string by this method.
+         *
+         * @throws IOException - indicates a failure when trying to determine the content type of a stream, will
+         * never occur when the content is coming from File
+         */
+        private void autosetContentType() throws IOException
+        {
+            final String mimeType = AUTOSET_CONTENT_TYPE
+                    ? this.source != null
+                        ? URLConnection.guessContentTypeFromName( source.getName() )
+                        : this.stream != null
+                            ? URLConnection.guessContentTypeFromStream( this.stream )
+                            : null
+                    : null;
+            if ( mimeType != null && !mimeType.isEmpty() )
+            {
+                setContentType( mimeType );
+            }
+
         }
 
         public Resource getResource()
@@ -279,6 +332,20 @@ public boolean isStreaming()
     private static final boolean SSL_ALLOW_ALL =
         Boolean.valueOf( System.getProperty( "maven.wagon.http.ssl.allowall", "false" ) );
 
+    /**
+     * If enabled, then the content-type HTTP header will be set using the file extension
+     * or the stream header to determine the type, <b>enabled by default</b>
+     */
+    private static final boolean AUTOSET_CONTENT_TYPE =
+            Boolean.valueOf( System.getProperty( "maven.wagon.http.autocontenttype", "true" ) );
+
+    /**
+     * If enabled, then an when determining the content type will result in a fatal exception
+     * <b>disabled by default</b>
+     * This flag is only effective when maven.wagon.http.autocontenttype is set.
+     */
+    private static final boolean AUTOSET_CONTENT_TYPE_FATAL =
+            Boolean.valueOf( System.getProperty( "maven.wagon.http.autocontenttype.fatal", "false" ) );
 
     /**
      * Maximum concurrent connections per distinct route.