do not crash on "=" in solution path

CHANGELOG.md

@@ -3,6 +3,7 @@ All changes to the project will be documented in this file.
 
 ## [1.34.9] - not yet released
 * Do not set mono paths when running in standalone mode ([omnisharp-vscode#3410](https://github.com/OmniSharp/omnisharp-vscode/issues/3410), [omnisharp-vscode#3340](https://github.com/OmniSharp/omnisharp-vscode/issues/3340), [#1650](https://github.com/OmniSharp/omnisharp-roslyn/issues/1650), PR:[#1656](https://github.com/OmniSharp/omnisharp-roslyn/pull/1656))
+* Fixed a bug where OmniSharp would crash on startup if the path contained `=` sign ([omnisharp-vscode#3436](https://github.com/OmniSharp/omnisharp-vscode/issues/3436), PR:[#1661](https://github.com/OmniSharp/omnisharp-roslyn/pull/1661))
 
 ## [1.34.8] - 2019-11-21
 * Update to Roslyn `3.5.0-beta1-19571-01` (PR:[#1653](https://github.com/OmniSharp/omnisharp-roslyn/pull/1653))

src/OmniSharp.Host/CommandLineApplication.cs

@@ -36,11 +36,29 @@ public CommandLineApplication()
             _debug = Application.Option("-d | --debug", "Wait for debugger to attach", CommandOptionType.NoValue);
         }
 
-        public int Execute(IEnumerable<string> args)
+        public int Execute(string[] args)
         {
             // omnisharp.json arguments should not be parsed by the CLI args parser
             // they will contain "=" so we should filter them out
-            OtherArgs = args.Where(x => x.Contains("="));
+            var extraArgs = new List<string>();
+            for (var i = 0; i < args.Length; i++)
+            {
+                // we are interested in arg with "=" if it's first
+                // or not-first but not preceded by "-s" or "--source"
+                if (args[i] != null && args[i].Contains("="))
+                {
+                    if (i == 0)
+                    {
+                        extraArgs.Add(args[i]);
+                    }
+                    else if (!args[i - 1].Equals("-s", StringComparison.OrdinalIgnoreCase) && !args[i - 1].Equals("--source", StringComparison.OrdinalIgnoreCase))
+                    {
+                        extraArgs.Add(args[i]);
+                    }
+                }
+            }
+
+            OtherArgs = extraArgs;
             return Application.Execute(args.Except(OtherArgs).ToArray());
         }
 

tests/OmniSharp.Tests/CommandLineApplicationFacts.cs

@@ -0,0 +1,28 @@
+using System.Linq;
+using Xunit;
+
+namespace OmniSharp.Tests
+{
+    public class CommandLineApplicationFacts
+    {
+        [InlineData("-s", @"\path\to\my-solution\foo", "a=b")]
+        [InlineData("--source", @"\path\to\my-solution\foo", "a=b")]
+        [InlineData("-s", @"\path\to\my=solution\foo", "a=b")]
+        [InlineData("--source", @"\path\to\my=solution\foo", "a=b")]
+        [InlineData("a=b", "-s", @"\path\to\my-solution\foo")]
+        [InlineData("a=b", "--source", @"\path\to\my-solution\foo")]
+        [InlineData("a=b", "-s", @"\path\to\my=solution\foo")]
+        [InlineData("a=b", "--source", @"\path\to\my=solution\foo")]
+        [InlineData("a=b", null, null)]
+        [Theory]
+        public void AllowsEqualsSignInSolutionPath(string arg1, string arg2, string arg3)
+        {
+            var app = new CommandLineApplication();
+            app.OnExecute(() => 0);
+            app.Execute(new[] { arg1, arg2, arg3 });
+
+            Assert.Single(app.OtherArgs);
+            Assert.Equal("a=b", app.OtherArgs.First());
+        }
+    }
+}