BUG-2693: This should fix an issue where Greenshot doesn't detect a MAPI client, we weren't looking at the 32 bit location.

GreenshotPlugin/Core/EmailConfigHelper.cs

@@ -1,6 +1,6 @@
 /*
  * Greenshot - a free and open source screenshot tool
- * Copyright (C) 2007-2020 Thomas Braun, Jens Klingen, Robin Krom
+ * Copyright (C) 2007-2021 Thomas Braun, Jens Klingen, Robin Krom
  * 
  * For more information see: http://getgreenshot.org/
  * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
@@ -18,46 +18,25 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
 using System.IO;
-using Microsoft.Win32;
 
 namespace GreenshotPlugin.Core {
 	/// <summary>
 	/// Description of EmailConfigHelper.
 	/// </summary>
 	public static class EmailConfigHelper {
-		private const string OutlookPathKey = @"SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\OUTLOOK.EXE";
-		private const string MapiClientKey = @"SOFTWARE\Clients\Mail";
-		private const string MapiLocationKey = @"SOFTWARE\Microsoft\Windows Messaging Subsystem";
-		private const string MapiKey = @"MAPI";
 
-		public static string GetMapiClient() {
-			using (RegistryKey key = Registry.CurrentUser.OpenSubKey(MapiClientKey, false)) {
-				if (key != null) {
-					return (string)key.GetValue(string.Empty);
-				} 
-			}
-			using (RegistryKey key = Registry.LocalMachine.OpenSubKey(MapiClientKey, false))
-			{
-				return (string) key?.GetValue(string.Empty);
-			}
-		}
-
-		public static bool HasMapi()
-        {
-            using RegistryKey key = Registry.LocalMachine.OpenSubKey(MapiLocationKey, false);
-            return key != null && "1".Equals(key.GetValue(MapiKey, "0"));
-        }
+		public static string GetMapiClient() => RegistryHelper.ReadLocalMachineSoftwareKey(@"Clients\Mail");
 		
-		public static string GetOutlookExePath() {
-			using (RegistryKey key = Registry.LocalMachine.OpenSubKey(OutlookPathKey, false)) {
-				if (key != null) {
-					// "" is the default key, which should point to the outlook location
-					return (string)key.GetValue(string.Empty);
-				}
-			}
-			return null;
+		public static bool HasMapi()
+		{
+			var value = RegistryHelper.ReadLocalMachineSoftwareKey(@"Microsoft\Windows Messaging Subsystem", "MAPI", "0");
+			return "1".Equals(value);
+
 		}
+		
+		public static string GetOutlookExePath() => RegistryHelper.ReadLocalMachineSoftwareKey(@"Microsoft\Windows\CurrentVersion\App Paths\OUTLOOK.EXE");
 
 		/// <summary>
 		/// Check if Outlook is installed
@@ -65,12 +44,11 @@ namespace GreenshotPlugin.Core {
 		/// <returns>Returns true if outlook is installed</returns>
 		public static bool HasOutlook() {
 			string outlookPath = GetOutlookExePath();
-			if (outlookPath != null) {
-				if (File.Exists(outlookPath)) {
-					return true;
-				}
+			if (outlookPath == null)
+			{
+				return false;
 			}
-			return false;
+			return File.Exists(outlookPath);
 		}
 	}
 }

GreenshotPlugin/Core/RegistryHelper.cs

@@ -0,0 +1,66 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2021 Thomas Braun, Jens Klingen, Robin Krom
+ * 
+ * For more information see: http://getgreenshot.org/
+ * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 1 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+using System;
+using Microsoft.Win32;
+
+namespace GreenshotPlugin.Core
+{
+    /// <summary>
+    /// A helper class for accessing the registry
+    /// </summary>
+    public static class RegistryHelper
+    {
+        /// <summary>
+        /// Retrieve a registry value
+        /// </summary>
+        /// <param name="keyName">string with the name of the key</param>
+        /// <param name="value">string with the name of the value below the key, null will retrieve the default</param>
+        /// <param name="defaultValue">string with the default value to return</param>
+        /// <returns>string with the value</returns>
+        public static string ReadLocalMachineSoftwareKey(string keyName, string value = null, string defaultValue = null)
+        {
+            string result = null;
+            value ??= string.Empty;
+            if (Environment.Is64BitOperatingSystem)
+            {
+                using var key = Registry.LocalMachine.OpenSubKey($@"SOFTWARE\{keyName}", false);
+                
+                if (key != null)
+                {
+                    result = (string)key.GetValue(value, defaultValue);
+                }
+            }
+
+            if (string.IsNullOrEmpty(result))
+            {
+                using var key = Registry.LocalMachine.OpenSubKey($@"SOFTWARE\wow6432node\{keyName}", false);
+
+                if (key != null)
+                {
+                    result = (string)key.GetValue(value, defaultValue);
+                }
+            }
+
+            return result;
+        }
+    }
+}