From 88282637959947fe1c949ed1cba5987c9696f86d Mon Sep 17 00:00:00 2001
From: Ethan Chiu <ethanchewy@github.com>
Date: Wed, 8 Jul 2020 14:00:12 -0400
Subject: [PATCH] Address situation if FileTable is null + add sanity check for
 adding file to fileTable

---
 src/Runner.Worker/ActionManifestManager.cs | 10 +++++++---
 src/Runner.Worker/ExecutionContext.cs      |  4 ++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/Runner.Worker/ActionManifestManager.cs b/src/Runner.Worker/ActionManifestManager.cs
index a9eac9d9d..138755047 100644
--- a/src/Runner.Worker/ActionManifestManager.cs
+++ b/src/Runner.Worker/ActionManifestManager.cs
@@ -74,8 +74,12 @@ namespace GitHub.Runner.Worker
                 var fileId = templateContext.GetFileId(fileRelativePath);
 
                 // Add this file to the FileTable in executionContext if it hasn't been added already
-                // we use > since fileID is zero indexed
-                if (fileId > executionContext.FileTable?.Count)
+                // we use > since fileID is 1 indexed
+                if (executionContext.FileTable == null)
+                {
+                    executionContext.FileTable = new string[0];
+                }
+                else if (fileId > executionContext.FileTable.Count)
                 {
                     executionContext.FileTable.Add(fileRelativePath);
                 }
@@ -136,7 +140,7 @@ namespace GitHub.Runner.Worker
             if (actionDefinition.Execution == null)
             {
                 executionContext.Debug($"Loaded action.yml file: {StringUtil.ConvertToJson(actionDefinition)}");
-                throw new ArgumentException($"Top level 'runs:' section is required for {manifestFile}");
+                throw new ArgumentException($"Top level 'runs:' section is required for {fileRelativePath}");
             }
             else
             {
diff --git a/src/Runner.Worker/ExecutionContext.cs b/src/Runner.Worker/ExecutionContext.cs
index 83e47c74c..4655151a4 100644
--- a/src/Runner.Worker/ExecutionContext.cs
+++ b/src/Runner.Worker/ExecutionContext.cs
@@ -53,7 +53,7 @@ namespace GitHub.Runner.Worker
         Dictionary<string, VariableValue> JobOutputs { get; }
         IDictionary<String, String> EnvironmentVariables { get; }
         IDictionary<String, ContextScope> Scopes { get; }
-        IList<String> FileTable { get; }
+        IList<String> FileTable { get; set; }
         StepsContext StepsContext { get; }
         DictionaryContextData ExpressionValues { get; }
         IList<IFunctionInfo> ExpressionFunctions { get; }
@@ -150,7 +150,7 @@ namespace GitHub.Runner.Worker
         public Dictionary<string, VariableValue> JobOutputs { get; private set; }
         public IDictionary<String, String> EnvironmentVariables { get; private set; }
         public IDictionary<String, ContextScope> Scopes { get; private set; }
-        public IList<String> FileTable { get; private set; }
+        public IList<String> FileTable { get; set; }
         public StepsContext StepsContext { get; private set; }
         public DictionaryContextData ExpressionValues { get; } = new DictionaryContextData();
         public IList<IFunctionInfo> ExpressionFunctions { get; } = new List<IFunctionInfo>();