From a4a2396c20a345c208d58a8652814a46e39b4800 Mon Sep 17 00:00:00 2001
From: Snorri Beck Gislason <snorri.beck@gmail.com>
Date: Wed, 9 Oct 2024 22:48:27 +0000
Subject: [PATCH] Always honor ProjectGuid, if provided (#615)

* Always honor ProjectGuid, if provided

* Upgrade System.Text.Json (#616)

Co-authored-by: Snorri Gislason <snbeck@microsoft.com>

* Always honor ProjectGuid, if provided

* Don't require ProjectGuid for legacy projects

---------

Co-authored-by: Snorri Gislason <snbeck@microsoft.com>
---
 .../SlnProject.cs                             | 37 ++++++++++---------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/src/Microsoft.VisualStudio.SlnGen/SlnProject.cs b/src/Microsoft.VisualStudio.SlnGen/SlnProject.cs
index b29675b..a13e439 100644
--- a/src/Microsoft.VisualStudio.SlnGen/SlnProject.cs
+++ b/src/Microsoft.VisualStudio.SlnGen/SlnProject.cs
@@ -293,25 +293,28 @@ internal static bool GetIsDeployable(Project project, string projectFileExtensio
         /// <returns>The GUID of the specified project.</returns>
         internal static Guid GetProjectGuid(Project project, bool isUsingMicrosoftNETSdk)
         {
-            Guid projectGuid = Guid.NewGuid();
+            Guid projectGuid;
 
-            if (!isUsingMicrosoftNETSdk && !Guid.TryParse(project.GetPropertyValueOrDefault(MSBuildPropertyNames.ProjectGuid, projectGuid.ToString()), out projectGuid))
-            {
-                string projectGuidValue = project.GetPropertyValueOrDefault(MSBuildPropertyNames.ProjectGuid, projectGuid.ToString());
+            string projectGuidValue = project.GetPropertyValue(MSBuildPropertyNames.ProjectGuid);
+            bool projectGuidIsEmpty = string.IsNullOrEmpty(projectGuidValue);
 
-                if (!Guid.TryParse(projectGuidValue, out projectGuid))
-                {
-                    throw new InvalidProjectFileException(
-                        projectFile: project.FullPath,
-                        lineNumber: 0,
-                        columnNumber: 0,
-                        endLineNumber: 0,
-                        endColumnNumber: 0,
-                        message: $"The {MSBuildPropertyNames.ProjectGuid} property value \"{projectGuidValue}\" is not a valid GUID.",
-                        errorSubcategory: null,
-                        errorCode: null,
-                        helpKeyword: null);
-                }
+            // If a ProjectGuid is provided it should be honored (regardless of project style) and must be valid
+            if (projectGuidIsEmpty)
+            {
+                projectGuid = Guid.NewGuid();
+            }
+            else if (!Guid.TryParse(projectGuidValue, out projectGuid))
+            {
+                throw new InvalidProjectFileException(
+                    projectFile: project.FullPath,
+                    lineNumber: 0,
+                    columnNumber: 0,
+                    endLineNumber: 0,
+                    endColumnNumber: 0,
+                    message: $"The {MSBuildPropertyNames.ProjectGuid} property value \"{projectGuidValue}\" is not a valid GUID.",
+                    errorSubcategory: null,
+                    errorCode: null,
+                    helpKeyword: null);
             }
 
             return projectGuid;