CHOP-900: Use new apr_procattr_constrain_handle_set() extension.

Now LLProcess explicitly requests APR to limit the handles passed to any child
process, instead of wantonly passing whatever happens to be lying around the
parent process at the time.
This requires the latest APR build.
Also revert LLUpdateDownloader::Implementation::mDownloadStream to llofstream
(as in rev 1878a57aebd7) instead of apr_file_t*. Using APR for that file was a
Band-Aid -- a single whacked mole -- for the problem more systemically
addressed by apr_procattr_constrain_handle_set().

1 files changed, 17 insertions, 0 deletions

diff --git a/indra/llcommon/llprocess.cpp b/indra/llcommon/llprocess.cpp
index 760be6da9b..9667e4e033 100644
--- a/indra/llcommon/llprocess.cpp
+++ b/indra/llcommon/llprocess.cpp
@@ -539,6 +539,23 @@ LLProcess::LLProcess(const LLSDOrParams& params):
 	apr_procattr_t *procattr = NULL;
 	chkapr(apr_procattr_create(&procattr, gAPRPoolp));
 
+	// IQA-490, CHOP-900: On Windows, ask APR to jump through hoops to
+	// constrain the set of handles passed to the child process. Before we
+	// changed to APR, the Windows implementation of LLProcessLauncher called
+	// CreateProcess(bInheritHandles=FALSE), meaning to pass NO open handles
+	// to the child process. Now that we support pipes, though, we must allow
+	// apr_proc_create() to pass bInheritHandles=TRUE. But without taking
+	// special pains, that causes trouble in a number of ways, due to the fact
+	// that the viewer is constantly opening and closing files -- most of
+	// which CreateProcess() passes to every child process!
+#if ! defined(APR_HAS_PROCATTR_CONSTRAIN_HANDLE_SET)
+	// Our special preprocessor symbol isn't even defined -- wrong APR
+	LL_WARNS("LLProcess") << "This version of APR lacks Linden "
+						  << "apr_procattr_constrain_handle_set() extension" << LL_ENDL;
+#else
+	chkapr(apr_procattr_constrain_handle_set(procattr, 1));
+#endif
+
 	// For which of stdin, stdout, stderr should we create a pipe to the
 	// child? In the viewer, there are only a couple viable
 	// apr_procattr_io_set() alternatives: inherit the viewer's own stdxxx