CTest: Capture test stdout/stderr through one pipe (#15600)

Use the KWSys Process "MergeOutput" option to give each test child
process the same pipe for both stdout and stderr.  This allows natural
merging of stdout and stderr together instead of merging on arbitrary
buffered read boundaries as before.

1 files changed, 2 insertions, 5 deletions

diff --git a/Source/CTest/cmProcess.h b/Source/CTest/cmProcess.h
index 1479df0..eddeeab 100644
--- a/Source/CTest/cmProcess.h
+++ b/Source/CTest/cmProcess.h
@@ -48,8 +48,7 @@ public:
    * Read one line of output but block for no more than timeout.
    * Returns:
    *   cmsysProcess_Pipe_None    = Process terminated and all output read
-   *   cmsysProcess_Pipe_STDOUT  = Line came from stdout
-   *   cmsysProcess_Pipe_STDOUT  = Line came from stderr
+   *   cmsysProcess_Pipe_STDOUT  = Line came from stdout or stderr
    *   cmsysProcess_Pipe_Timeout = Timeout expired while waiting
    */
   int GetNextOutputLine(std::string& line, double timeout);
@@ -68,13 +67,11 @@ private:
     bool GetLine(std::string& line);
     bool GetLast(std::string& line);
   };
-  Buffer StdErr;
-  Buffer StdOut;
+  Buffer Output;
   std::string Command;
   std::string WorkingDirectory;
   std::vector<std::string> Arguments;
   std::vector<const char*> ProcessArgs;
-  std::string Output;
   int Id;
   int ExitValue;
 };