Bug#715633: Crash: Proposing fix

[Martin Steghöfer <martin@steghoefer.eu>]

The crash referenced in the mayhem data occurs whenever the "--pidfile" 
option is used (no matter what the argument).

The problem has been introduced by Debian, in the debian patch 
"add_pidfile_option.patch": The new argument "pidfile" is defined with 
the "no_argument" specifier, but the argument processing switch tries to 
call "strdup" on "optarg" - which is never set.

Trivial fix:

As the "pidfile" option doesn't have any effect, if "gconf.pidfile" 
isn't set to anything non-NULL, I guess that the argument is really 
mandatory. So change the "no_argument" specifier in line 102 of the 
patch to "required_argument".

I attach a new (fixed) version of the patch.

Cheers,
Martin

--- ample-0.5.7.orig/src/ample.c
+++ ample-0.5.7/src/ample.c
@@ -241,6 +241,26 @@
 	return;
 }
 
+/*
+ * Write a pidfile
+ * 
+ * Added by Debian Maintainer
+ *
+ */
+static int
+do_pidfile(void)
+{
+	FILE *f;
+	int pidnum;
+	pidnum = getpid();
+	f = fopen(gconf.pidfile, "w");
+	if (!f) {
+		return (1);
+	}
+	fprintf(f,"%d\n", pidnum);
+	fclose(f);
+	return(0);
+}
 
 /*
  * Checks if a file descriptor is a socket.
@@ -292,6 +312,15 @@
 		die("fork");
 }
 
+/* Remove pidfile when dies
+ * 
+ */
+static void
+removepidfile(void)
+{
+	unlink(gconf.pidfile);
+	exit(EXIT_SUCCESS);
+}
 
 /*
  * Prepares the proper way for ample to log messages.
@@ -460,6 +489,18 @@
 	checkopt(argc, argv);	
 	gconf.inetd = issocket(0);
 	daemonize();
+
+	/* Added by Debian Maintainer */
+	if (gconf.pidfile) {
+		debug (1, "pidfile:%s \n", gconf.pidfile);
+		if (do_pidfile() != 0) {
+			debug(1, "could not write pidfile");
+			exit(1);
+		}
+
+	}
+	/**/
+
 	preparelog();
 	if(!gconf.inetd)
 		logmsg("Ample/%s started\n", AMPLE_VERSION);
@@ -488,6 +529,12 @@
 	memset(&sa, 0, sizeof(sa));
 	sa.sa_handler = sigchild_handler;
 	sigaction(SIGCHLD, &sa, NULL);
+	
+	/* Added by the Debian Maintainer */
+	if (signal(SIGTERM, removepidfile) == SIG_ERR) {
+		debug(1, "err, I can't quit");
+	}
+	/**/
 	sigemptyset(&chld);
 	sigaddset(&chld, SIGCHLD);
 
--- ample-0.5.7.orig/src/ample.h
+++ ample-0.5.7/src/ample.h
@@ -36,6 +36,7 @@
 	char * servername;
 	char * serveraddress;
 	char * filter;
+	char * pidfile;
 };
 
 struct childstat {
--- ample-0.5.7.orig/src/configuration.c
+++ ample-0.5.7/src/configuration.c
@@ -621,6 +621,7 @@
 		{"servername", OPT_STRING, &gconf.servername},
 		{"serveraddress", OPT_STRING, &gconf.serveraddress},		
 		{"username", OPT_STRING, &gconf.username},
+		{"pidfile", OPT_STRING, &gconf.pidfile},
 		{NULL, 0, NULL}
 	};
 	
@@ -674,13 +675,14 @@
 		{"debug", optional_argument, NULL, 'd'},
 		{"trace", no_argument, NULL, 't'},
 		{"version", no_argument, NULL, 'v'},
+		{"pidfile", required_argument, NULL, 'i'},
 		{NULL, 0, NULL, 0}
 	};
 
-	while((c = getopt_long(argc, argv, "p:oc:nf:m:hd::tv", longopts, &i)) 
+	while((c = getopt_long(argc, argv, "p:oc:nf:m:hd::ti:v", longopts, &i)) 
 	      != -1) {
 #else
-	while((c = getopt(argc, argv, "p:oc:nf:m:hd::tv")) != -1) {
+	while((c = getopt(argc, argv, "p:oc:nf:m:hd::ti:v")) != -1) {
 #endif
 		switch(c) {
 		case 'p':
@@ -718,6 +720,9 @@
 		case 'v':
 			printf("Ample version %s\n", AMPLE_VERSION);
 			exit(0);
+		case 'i':
+			gconf.pidfile = strdup(optarg);
+			break;
 		default:
 			usage(TRUE);
 		}
--- ample-0.5.7.orig/src/configuration.h
+++ ample-0.5.7/src/configuration.h
@@ -70,6 +70,7 @@
                               higher number means more detail\n\
   -t, --trace                 no forking, no backgrounding\n\
                               helpful when debugging\n\
+  -i, --pidfile               create a pidfile \n\
   -v, --version               output version information and exit\n\
 \n\
 Report bugs to <david@2gen.com>\n"
@@ -86,7 +87,8 @@
   -d[=NUMBER]                 debug messages will be printed,\n\
                               higher number means more detail\n\
   -t                          no forking, no backgrounding,\n\
-                              helpful when debugging)\n\
+                              (helpful when debugging)\n\
+  -i                          create a pidfile \n\
   -v                          output version information and exit\n\
 \n\
 Report bugs to <david@2gen.com>\n"
--- ample-0.5.7.orig/docs/ample.1.in
+++ ample-0.5.7/docs/ample.1.in
@@ -86,6 +86,9 @@
 .B -v --version
 Display version information and exit.
 .TP
+.B -i --pidfile [PIDFILE]
+Write a PIDFILE to handle ample as a daemon
+.TP
 .BI "[" "PATH" "...]"
 These are path(s) to files or directories that Ample can use to 
 populate it's list of MP3's. If