From 941868e8d7ee2b749ffd2652dc18ab91401a1752 Mon Sep 17 00:00:00 2001
From: Stephan Witt <switt@lyx.org>
Date: Sun, 16 Nov 2014 17:21:46 +0100
Subject: [PATCH] #9317 add method cleanDuplicateEnvVars() to correct the
 broken environment with duplicate PATH values passed by Yosemite's launchd(8)

---
 src/LyX.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/src/LyX.cpp b/src/LyX.cpp
index 023f80dfc1..f805456cc7 100644
--- a/src/LyX.cpp
+++ b/src/LyX.cpp
@@ -77,6 +77,10 @@
 using namespace std;
 using namespace lyx::support;
 
+#if defined (USE_MACOSX_PACKAGING)
+#include <crt_externs.h>
+#endif
+
 namespace lyx {
 
 namespace Alert = frontend::Alert;
@@ -706,6 +710,55 @@ void LyX::printError(ErrorItem const & ei)
 	cerr << to_utf8(tmp) << endl;
 }
 
+#if defined (USE_MACOSX_PACKAGING)
+namespace {
+	// Unexposed--extract an environment variable name from its NAME=VALUE
+	// representation
+	std::string varname(const char* line)
+	{
+		size_t nameLen = strcspn(line, "=");
+		if (nameLen == strlen(line)) {
+			return std::string();
+		} else {
+			return std::string(line, nameLen);
+		}
+	}
+}
+	
+void cleanDuplicateEnvVars()
+{
+	std::set<std::string> seen;
+	std::set<std::string> dupes;
+
+	// Create a list of the environment variables that appear more than once
+	for (char **read = *_NSGetEnviron(); *read; read++) {
+		std::string name = varname(*read);
+		if (name.size() == 0) {
+			continue;
+		}
+		if (seen.find(name) != seen.end()) {
+			dupes.insert(name);
+		} else {
+			seen.insert(name);
+		}
+	}
+
+	// Loop over the list of duplicated variables
+	for (std::set<std::string>::iterator dupe = dupes.begin(); dupe != dupes.end(); dupe++) {
+		const char *name = (*dupe).c_str();
+		char *val = getenv(name);
+		if (val != NULL) {
+			LYXERR(Debug::INIT, "Duplicate environment variable: " << name);
+			// unsetenv removes *all* instances of the variable from the environment
+			unsetenv(name);
+
+			// replace with the value from getenv (in practice appears to be the
+			// first value in the list)
+			setenv(name, val, 0);
+		}
+	}
+}
+#endif
 
 bool LyX::init()
 {
@@ -718,6 +771,10 @@ bool LyX::init()
 	signal(SIGTERM, error_handler);
 	// SIGPIPE can be safely ignored.
 
+#if defined (USE_MACOSX_PACKAGING)
+	cleanDuplicateEnvVars();
+#endif
+
 	lyxrc.tempdir_path = package().temp_dir().absFileName();
 	lyxrc.document_path = package().document_dir().absFileName();
 
-- 
2.39.2