From 2e99949ccb216c59ff1932bc3773654e9ae54419 Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Tue, 10 Jul 2012 10:55:02 -0400
Subject: [PATCH] include: Ignore empty string as file name (#13388)

Previously CMake silently accepted the empty string and added a bogus
dependency on the current directory.  Instead warn about the empty file
name and ignore it.  We cannot make this an error because there may be
existing projects that accidentally depend on the old behavior.

Add a RunCMake.include test to cover this case.
---
 Source/cmIncludeCommand.cxx                           | 7 +++++++
 Tests/RunCMake/CMakeLists.txt                         | 1 +
 Tests/RunCMake/include/CMakeLists.txt                 | 3 +++
 Tests/RunCMake/include/EmptyString-stderr.txt         | 5 +++++
 Tests/RunCMake/include/EmptyString.cmake              | 1 +
 Tests/RunCMake/include/EmptyStringOptional-stderr.txt | 5 +++++
 Tests/RunCMake/include/EmptyStringOptional.cmake      | 1 +
 Tests/RunCMake/include/RunCMakeTest.cmake             | 4 ++++
 8 files changed, 27 insertions(+)
 create mode 100644 Tests/RunCMake/include/CMakeLists.txt
 create mode 100644 Tests/RunCMake/include/EmptyString-stderr.txt
 create mode 100644 Tests/RunCMake/include/EmptyString.cmake
 create mode 100644 Tests/RunCMake/include/EmptyStringOptional-stderr.txt
 create mode 100644 Tests/RunCMake/include/EmptyStringOptional.cmake
 create mode 100644 Tests/RunCMake/include/RunCMakeTest.cmake

diff --git a/Source/cmIncludeCommand.cxx b/Source/cmIncludeCommand.cxx
index 0ac6df46a..0d5f67b78 100644
--- a/Source/cmIncludeCommand.cxx
+++ b/Source/cmIncludeCommand.cxx
@@ -70,6 +70,13 @@ bool cmIncludeCommand
         }
     }
 
+  if(fname.empty())
+    {
+    this->Makefile->IssueMessage(cmake::AUTHOR_WARNING,
+                                 "include() given empty file name (ignored).");
+    return true;
+    }
+
   if(!cmSystemTools::FileIsFullPath(fname.c_str()))
     {
     // Not a path. Maybe module.
diff --git a/Tests/RunCMake/CMakeLists.txt b/Tests/RunCMake/CMakeLists.txt
index 23fc086d8..eca96f907 100644
--- a/Tests/RunCMake/CMakeLists.txt
+++ b/Tests/RunCMake/CMakeLists.txt
@@ -50,6 +50,7 @@ add_RunCMake_test(ObjectLibrary)
 
 add_RunCMake_test(build_command)
 add_RunCMake_test(find_package)
+add_RunCMake_test(include)
 add_RunCMake_test(list)
 
 if("${CMAKE_TEST_GENERATOR}" MATCHES "Visual Studio [^6]")
diff --git a/Tests/RunCMake/include/CMakeLists.txt b/Tests/RunCMake/include/CMakeLists.txt
new file mode 100644
index 000000000..e8db6b05b
--- /dev/null
+++ b/Tests/RunCMake/include/CMakeLists.txt
@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 2.8)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)
diff --git a/Tests/RunCMake/include/EmptyString-stderr.txt b/Tests/RunCMake/include/EmptyString-stderr.txt
new file mode 100644
index 000000000..006c647c6
--- /dev/null
+++ b/Tests/RunCMake/include/EmptyString-stderr.txt
@@ -0,0 +1,5 @@
+CMake Warning \(dev\) at EmptyString.cmake:1 \(include\):
+  include\(\) given empty file name \(ignored\).
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
diff --git a/Tests/RunCMake/include/EmptyString.cmake b/Tests/RunCMake/include/EmptyString.cmake
new file mode 100644
index 000000000..4285cb3d5
--- /dev/null
+++ b/Tests/RunCMake/include/EmptyString.cmake
@@ -0,0 +1 @@
+include("")
diff --git a/Tests/RunCMake/include/EmptyStringOptional-stderr.txt b/Tests/RunCMake/include/EmptyStringOptional-stderr.txt
new file mode 100644
index 000000000..b61c67912
--- /dev/null
+++ b/Tests/RunCMake/include/EmptyStringOptional-stderr.txt
@@ -0,0 +1,5 @@
+CMake Warning \(dev\) at EmptyStringOptional.cmake:1 \(include\):
+  include\(\) given empty file name \(ignored\).
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
diff --git a/Tests/RunCMake/include/EmptyStringOptional.cmake b/Tests/RunCMake/include/EmptyStringOptional.cmake
new file mode 100644
index 000000000..549d46b3d
--- /dev/null
+++ b/Tests/RunCMake/include/EmptyStringOptional.cmake
@@ -0,0 +1 @@
+include("" OPTIONAL)
diff --git a/Tests/RunCMake/include/RunCMakeTest.cmake b/Tests/RunCMake/include/RunCMakeTest.cmake
new file mode 100644
index 000000000..59b87ca75
--- /dev/null
+++ b/Tests/RunCMake/include/RunCMakeTest.cmake
@@ -0,0 +1,4 @@
+include(RunCMake)
+
+run_cmake(EmptyString)
+run_cmake(EmptyStringOptional)