Workaround to launch URLs

ConsoleUI/ModInfoScreen.cs

@@ -219,10 +219,7 @@ public static bool LaunchURL(Uri u)
             // then wait 1.5 seconds and refresh the screen when it closes.
             ConsoleMessageDialog d = new ConsoleMessageDialog("Launching...", new List<string>());
             d.Run(() => {
-                Process.Start(new ProcessStartInfo() {
-                    UseShellExecute = true,
-                    FileName        = u.ToString()
-                });
+                Utilities.ProcessStartURL(u.ToString());
                 System.Threading.Thread.Sleep(1500);
             });
             return true;

Core/Utilities.cs

@@ -1,7 +1,9 @@
 using System;
 using System.IO;
+using System.Diagnostics;
 using System.Transactions;
 using ChinhDo.Transactions.FileManager;
+using log4net;
 
 namespace CKAN
 {
@@ -75,5 +77,50 @@ private static void _CopyDirectory(string sourceDirPath, string destDirPath, boo
                 }
             }
         }
+
+        /// <summary>
+        /// Launch a URL. For YEARS this was done by Process.Start in a
+        /// cross-platform way, but Microsoft chose to break that,
+        /// so now every .NET app has to write its own custom code for it,
+        /// with special code for each platform.
+        /// https://github.com/dotnet/corefx/issues/10361
+        /// </summary>
+        /// <param name="url">URL to launch</param>
+        /// <returns>
+        /// true if launched, false otherwise
+        /// </returns>
+        public static bool ProcessStartURL(string url)
+        {
+            try
+            {
+                if (Platform.IsMac)
+                {
+                    Process.Start("open", $"\"{url}\"");
+                    return true;
+                }
+                else if (Platform.IsUnix)
+                {
+                    Process.Start("xdg-open", $"\"{url}\"");
+                    return true;
+                }
+                else
+                {
+                    // Try the old way
+                    Process.Start(new ProcessStartInfo(url)
+                    {
+                        UseShellExecute = true,
+                        Verb            = "open"
+                    });
+                    return true;
+                }
+            }
+            catch (Exception exc)
+            {
+                log.Error($"Exception for URL {url}", exc);
+            }
+            return false;
+        }
+
+        private static readonly ILog log = LogManager.GetLogger(typeof(Utilities));
     }
 }

GUI/Main.cs

@@ -1151,7 +1151,7 @@ private void manageKspInstancesMenuItem_Click(object sender, EventArgs e)
 
         private void openKspDirectoryToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            Process.Start(Instance.manager.CurrentInstance.GameDir());
+            Utilities.ProcessStartURL(Instance.manager.CurrentInstance.GameDir());
         }
 
         private void CompatibleKspVersionsToolStripMenuItem_Click(object sender, EventArgs e)
@@ -1296,12 +1296,12 @@ private void MainTabControl_OnSelectedIndexChanged(object sender, EventArgs e)
 
         private void reportClientIssueToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            Process.Start("https://github.com/KSP-CKAN/CKAN/issues/new/choose");
+            Utilities.ProcessStartURL("https://github.com/KSP-CKAN/CKAN/issues/new/choose");
         }
 
         private void reportMetadataIssueToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            Process.Start("https://github.com/KSP-CKAN/NetKAN/issues/new/choose");
+            Utilities.ProcessStartURL("https://github.com/KSP-CKAN/NetKAN/issues/new/choose");
         }
 
         private void ModList_MouseDown(object sender, MouseEventArgs e)

GUI/MainInstall.cs

@@ -275,11 +275,7 @@ private void InstallMods(object sender, DoWorkEventArgs e)
                         // Launch the URL describing this host's throttling practices, if any
                         if (kraken.infoUrl != null)
                         {
-                            Process.Start(new ProcessStartInfo()
-                            {
-                                UseShellExecute = true,
-                                FileName        = kraken.infoUrl.ToString()
-                            });
+                            Utilities.ProcessStartURL(kraken.infoUrl.ToString());
                         }
                         // Now pretend they clicked the menu option for the settings
                         Enabled = false;
@@ -303,11 +299,7 @@ private void InstallMods(object sender, DoWorkEventArgs e)
                 {
                     if (GUI.user.RaiseYesNoDialog(Properties.Resources.MainInstallLibCurlMissing))
                     {
-                        Process.Start(new ProcessStartInfo()
-                        {
-                            UseShellExecute = true,
-                            FileName        = "https://github.com/KSP-CKAN/CKAN/wiki/libcurl"
-                        });
+                        Utilities.ProcessStartURL("https://github.com/KSP-CKAN/CKAN/wiki/libcurl");
                     }
                     throw;
                 }

GUI/MainModInfo.cs

@@ -114,7 +114,7 @@ private void ContentsDownloadButton_Click(object sender, EventArgs e)
 
         private void ContentsOpenButton_Click(object sender, EventArgs e)
         {
-            Process.Start(manager.Cache.GetCachedFilename(SelectedModule.ToModule()));
+            Utilities.ProcessStartURL(manager.Cache.GetCachedFilename(SelectedModule.ToModule()));
         }
 
         private void LinkLabel_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
@@ -604,7 +604,7 @@ internal void OpenFileBrowser(TreeNode node)
                 return;
             }
 
-            Process.Start(location);
+            Utilities.ProcessStartURL(location);
         }
     }
 }

GUI/MainModList.cs

@@ -583,7 +583,7 @@ private async void ModList_CellValueChanged(object sender, DataGridViewCellEvent
                 DataGridViewLinkCell cell = gridCell as DataGridViewLinkCell;
                 string cmd = cell?.Value.ToString();
                 if (!string.IsNullOrEmpty(cmd))
-                    Process.Start(cmd);
+                    Utilities.ProcessStartURL(cmd);
             }
             else
             {

GUI/ManageKspInstances.cs

@@ -207,7 +207,7 @@ private void OpenDirectoryMenuItem_Click(object sender, EventArgs e)
                 return;
             }
 
-            System.Diagnostics.Process.Start(path);
+            Utilities.ProcessStartURL(path);
         }
 
         private void RenameButton_Click(object sender, EventArgs e)

GUI/SettingsDialog.cs

@@ -225,12 +225,7 @@ private void ResetCacheButton_Click(object sender, EventArgs e)
 
         private void OpenCacheButton_Click(object sender, EventArgs e)
         {
-            Process.Start(new ProcessStartInfo()
-            {
-                FileName        = config.DownloadCacheDir,
-                UseShellExecute = true,
-                Verb            = "open"
-            });
+            Utilities.ProcessStartURL(config.DownloadCacheDir);
         }
 
         private void ReposListBox_SelectedIndexChanged(object sender, EventArgs e)

GUI/Util.cs

@@ -70,7 +70,9 @@ public static void HideConsoleWindow()
         public static bool CheckURLValid(string source)
         {
             Uri uri_result;
-            return Uri.TryCreate(source, UriKind.Absolute, out uri_result) && uri_result.Scheme == Uri.UriSchemeHttp;
+            return Uri.TryCreate(source, UriKind.Absolute, out uri_result)
+                && (uri_result.Scheme == Uri.UriSchemeHttp
+                 || uri_result.Scheme == Uri.UriSchemeHttps);
         }
 
         /// <summary>
@@ -95,30 +97,17 @@ public static bool TryOpenWebPage(string url, IEnumerable<string> prefixes = nul
         {
             // Default prefixes to try if not provided
             if (prefixes == null)
-                prefixes = new string[] { "http://", "https://" };
-
-            try // opening the page normally
             {
-                Process.Start(url);
-                return true; // we did it! return true
+                prefixes = new string[] { "https://", "http://" };
             }
-            catch (Exception) // something bad happened
+
+            foreach (string fullUrl in new string[] { url }
+                .Concat(prefixes.Select(p => p + url).Where(CheckURLValid)))
             {
-                foreach (string prefixed_url in prefixes.Select(p=>p+url).Where(CheckURLValid))
-                {
-                    try // with a new prefix
-                    {
-                        Process.Start(prefixed_url);
-                        return true;
-                    }
-                    catch (Exception)
-                    {
-                        // move along to the next prefix
-                    }
-                }
-                // We tried all prefixes, and still no luck.
-                return false;
+                if (Utilities.ProcessStartURL(fullUrl))
+                    return true;
             }
+            return false;
         }
 
         /// <summary>