SDL: test_harness: Report if zero tests to run.

SDL Commits
1 
From 6b4bd5a75924917e45c70d55596ac2d51267c19e Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sun, 5 Jun 2022 09:34:12 -0400
Subject: [PATCH] test_harness: Report if zero tests to run.

Fixes static analysis complain about a potential malloc(0) call.
---
 src/test/SDL_test_harness.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/test/SDL_test_harness.c b/src/test/SDL_test_harness.c
index 3a1f432b0b7..ec67d997786 100644
--- a/src/test/SDL_test_harness.c
+++ b/src/test/SDL_test_harness.c
@@ -443,6 +443,11 @@ int SDLTest_RunSuites(SDLTest_TestSuiteReference *testSuites[], const char *user
         }
     }
 
+    if (totalNumberOfTests == 0) {
+        SDLTest_LogError("No tests to run?");
+        return -1;
+    }
+
     /* Pre-allocate an array for tracking failed tests (potentially all test cases) */
     failedTests = (const SDLTest_TestCaseReference **)SDL_malloc(totalNumberOfTests * sizeof(SDLTest_TestCaseReference *));
     if (failedTests == NULL) {