Allow to unset LD_LIBRARY_PATH on exec

This is useful when using distro-packaged video-tools
(e.g. on Linux/ARM), or when running post-export commands.

libs/ardour/ardour/system_exec.h

@@ -28,9 +28,9 @@ namespace ARDOUR {
 class LIBARDOUR_API SystemExec : public PBD::SystemExec
 {
 public:
-	SystemExec (std::string c, std::string a = "");
-	SystemExec (std::string c, char** a);
-	SystemExec (std::string c, const std::map<char, std::string> subs);
+	SystemExec (std::string cmd, std::string argv = "", bool supress_ld_env = false);
+	SystemExec (std::string cmd, char** argv, bool supress_ld_env = false);
+	SystemExec (std::string cmd, const std::map<char, std::string> subs, bool supress_ld_env = false);
 	~SystemExec ();
 
 	int start (StdErrMode stderr_mode = IgnoreAndClose)

libs/ardour/system_exec.cc

@@ -56,20 +56,20 @@ SystemExec::initialize ()
 	_initialized = true;
 }
 
-SystemExec::SystemExec (std::string c, char** a)
-	: PBD::SystemExec (c, a)
+SystemExec::SystemExec (std::string cmd, char** argv, bool supress_ld_env)
+	: PBD::SystemExec (cmd, argv, supress_ld_env)
 {
 	initialize ();
 }
 
-SystemExec::SystemExec (std::string c, std::string a)
-	: PBD::SystemExec (c, a)
+SystemExec::SystemExec (std::string cmd, std::string argv, bool supress_ld_env)
+	: PBD::SystemExec (cmd, argv, supress_ld_env)
 {
 	initialize ();
 }
 
-SystemExec::SystemExec (std::string c, const std::map<char, std::string> subs)
-	: PBD::SystemExec (c, subs)
+SystemExec::SystemExec (std::string cmd, const std::map<char, std::string> subs, bool supress_ld_env)
+	: PBD::SystemExec (cmd, subs, supress_ld_env)
 {
 	initialize ();
 }

libs/pbd/pbd/system_exec.h

@@ -82,22 +82,23 @@ class LIBPBD_API SystemExec
 		 * The alternative constructor below allows to specify quoted parameters
 		 * incl. whitespace.
 		 *
-		 * @param c program pathname that identifies the new process image file.
-		 * @param a string of commandline-arguments to be passed to the new program.
+		 * @param cmd program pathname that identifies the new process image file.
+		 * @param argv string of commandline-arguments to be passed to the new program.
+		 * @param supress_ld_env  On Linux, unset LD_LIBRARY_PATH environment variable
 		 */
-		SystemExec (std::string c, std::string a = "");
+		SystemExec (std::string cmd, std::string argv = "", bool supress_ld_env = false);
 		/** similar to \ref SystemExec but allows to specify custom arguments
 		 *
-		 * @param c program pathname that identifies the new process image file.
-		 * @param a array of argument strings passed to the new program as 'argv'.
+		 * @param cmd program pathname that identifies the new process image file.
+		 * @param argv array of argument strings passed to the new program as 'argv'.
 		 *          it must be terminated by a null pointer (see the 'evecve'
 		 *          POSIX-C documentation for more information)
 		 *          The array must be dynamically allocated using malloc or strdup.
 		 *          Unless they're NULL, the array itself and each of its content
 		 *          memory is freed() in the destructor.
-		 *
+		 * @param supress_ld_env  On Linux, unset LD_LIBRARY_PATH environment variable
 		 */
-		SystemExec (std::string c, char ** a);
+		SystemExec (std::string cmd, char **argv, bool supress_ld_env = false);
 
 		/** similar to \ref SystemExec but expects a whole command line, and
 		 * handles some simple escape sequences.
@@ -111,10 +112,9 @@ class LIBPBD_API SystemExec
 		 * "\ " is non-splitting space, "\\" (and "\" at end of command) as "\",
 		 * for "%<char>", \<char\> is looked up in subs and the corresponding string
 		 * substituted. "%%" (and "%" at end of command)
-		 *
-		 * @returns an argv array suitable for creating a new SystemExec with
+		 * @param supress_ld_env  On Linux, unset LD_LIBRARY_PATH environment variable
 		 */
-		SystemExec (std::string command, const std::map<char, std::string> subs);
+		SystemExec (std::string command, const std::map<char, std::string> subs, bool supress_ld_env = false);
 
 		virtual ~SystemExec ();
 
@@ -231,7 +231,7 @@ class LIBPBD_API SystemExec
 
 		void make_argp(std::string);
 		void make_argp_escaped(std::string command, const std::map<char, std::string> subs);
-		void make_envp();
+		void make_envp (bool supress_ld_env);
 
 		char **argp;
 		char **envp;

libs/pbd/system_exec.cc

@@ -79,17 +79,17 @@ SystemExec::init ()
 #endif
 }
 
-SystemExec::SystemExec (std::string c, std::string a)
+SystemExec::SystemExec (std::string c, std::string a, bool supress_ld_env)
 	: cmd(c)
 {
 	init ();
 
 	argp = NULL;
-	make_envp();
+	make_envp (supress_ld_env);
 	make_argp(a);
 }
 
-SystemExec::SystemExec (std::string c, char **a)
+SystemExec::SystemExec (std::string c, char **a, bool supress_ld_env)
 	: cmd(c) , argp(a)
 {
 	init ();
@@ -97,10 +97,10 @@ SystemExec::SystemExec (std::string c, char **a)
 #ifdef PLATFORM_WINDOWS
 	make_wargs(a);
 #endif
-	make_envp();
+	make_envp (supress_ld_env);
 }
 
-SystemExec::SystemExec (std::string command, const std::map<char, std::string> subs)
+SystemExec::SystemExec (std::string command, const std::map<char, std::string> subs, bool supress_ld_env)
 {
 	init ();
 	make_argp_escaped(command, subs);
@@ -141,7 +141,7 @@ SystemExec::SystemExec (std::string command, const std::map<char, std::string> s
 	// Glib::find_program_in_path () is only available in Glib >= 2.28
 	// cmd = Glib::find_program_in_path (argp[0]);
 #endif
-	make_envp();
+	make_envp (supress_ld_env);
 }
 
 char*
@@ -364,7 +364,7 @@ CALLBACK my_terminateApp(HWND hwnd, LPARAM procId)
 /* PROCESS API */
 
 void
-SystemExec::make_envp()
+SystemExec::make_envp (bool)
 {
 	; /* environemt is copied over with CreateProcess(...,env=0 ,..) */
 }
@@ -594,12 +594,17 @@ SystemExec::write_to_stdin (const void* data, size_t bytes)
 extern char **environ;
 
 void
-SystemExec::make_envp()
+SystemExec::make_envp (bool supress_ld_env)
 {
 	int i = 0;
 	envp = (char **) calloc(1, sizeof(char*));
 	/* copy current environment */
 	for (i = 0; environ[i]; ++i) {
+#ifndef __APPLE__
+		if (supress_ld_env && 0 == strncmp (environ[i], "LD_LIBRARY_PATH=", 17)) {
+			continue;
+		}
+#endif
 	  envp[i] = strdup(environ[i]);
 	  envp = (char **) realloc(envp, (i+2) * sizeof(char*));
 	}