From: Christian Kastner <ckk@kvr.at>
Date: Sun, 20 Dec 2015 13:22:36 +0100
Subject: Miscellaneous code errors

These are mostly one-line fixes of obvious errors such as running into
undefined behaviour, missing arguments to functions, typos, name mix-ups, etc.
Creating separate patches for them would be overkill.

Originally by Steve Greenland <stevegr@debian.org>, occasionally modified to
match what upstream eventually did for ISC cron v4.1.

Forwarded: no
Last-Update: 2015-12-20
---
 compat.c     |  2 +-
 cron.c       |  4 ++--
 cron.h       |  5 +++--
 crontab.c    | 20 +++++++++++++-------
 database.c   |  4 ++--
 do_command.c | 22 ++++++++++------------
 env.c        |  5 ++++-
 misc.c       | 26 ++++++++++++++------------
 popen.c      |  4 ++--
 user.c       |  1 +
 10 files changed, 52 insertions(+), 41 deletions(-)

diff --git a/compat.c b/compat.c
index 205c731..1c7eb2d 100644
--- a/compat.c
+++ b/compat.c
@@ -227,7 +227,7 @@ setenv(name, value, overwrite)
 		return -1;
 	}
 
-	sprintf("%s=%s", name, value);
+	sprintf(tmp, "%s=%s", name, value);
 	return putenv(tmp);	/* intentionally orphan 'tmp' storage */
 }
 #endif
diff --git a/cron.c b/cron.c
index 2753a44..c2a7d18 100644
--- a/cron.c
+++ b/cron.c
@@ -246,7 +246,7 @@ cron_sleep() {
 
 #ifdef USE_SIGCHLD
 static void
-sigchld_handler(x) {
+sigchld_handler(int x) {
 	WAIT_T		waiter;
 	PID_T		pid;
 
@@ -276,7 +276,7 @@ sigchld_handler(x) {
 
 
 static void
-sighup_handler(x) {
+sighup_handler(int x) {
 	log_close();
 }
 
diff --git a/cron.h b/cron.h
index ebe45c7..a71dc17 100644
--- a/cron.h
+++ b/cron.h
@@ -105,7 +105,7 @@
 
 #if DEBUGGING
 # define Debug(mask, message) \
-			if ( (DebugFlags & (mask) ) == (mask) ) \
+			if ( (DebugFlags & (mask) )  ) \
 				printf message;
 #else /* !DEBUGGING */
 # define Debug(mask, message) \
@@ -205,6 +205,7 @@ int		job_runqueue __P((void)),
 		get_char __P((FILE *)),
 		get_string __P((char *, int, FILE *, char *)),
 		swap_uids __P((void)),
+		swap_uids_back __P((void)),
 		load_env __P((char *, FILE *)),
 		cron_pclose __P((FILE *)),
 		strcmp_until __P((char *, char *, int)),
@@ -220,7 +221,7 @@ char		*env_get __P((char *, char **)),
 		**env_set __P((char **, char *));
 
 user		*load_user __P((int, struct passwd *, char *)),
-		*find_user __P((cron_db *, char *));
+		*find_user __P((cron_db *, const char *));
 
 entry		*load_entry __P((FILE *, void (*)(),
 				 struct passwd *, char **));
diff --git a/crontab.c b/crontab.c
index 657af71..d8aecba 100644
--- a/crontab.c
+++ b/crontab.c
@@ -57,7 +57,7 @@ static char	*Options[] = { "???", "list", "delete", "edit", "replace" };
 static	PID_T		Pid;
 static	char		User[MAX_UNAME], RealUser[MAX_UNAME];
 static	char		Filename[MAX_FNAME];
-static	FILE		*NewCrontab;
+static	FILE		*NewCrontab = NULL;
 static	int		CheckErrorCount;
 static	enum opt_t	Option;
 static	struct passwd	*pw;
@@ -124,8 +124,14 @@ main(argc, argv)
 	case opt_replace:	if (replace_cmd() < 0)
 					exitstatus = ERROR_EXIT;
 				break;
-	}
-	exit(0);
+				/* The following was added to shut
+				 -Wall up, but it will never be hit,
+				 because the option parser will catch
+				 it */
+	case opt_unknown: usage("unknown option specified");
+	                  break;
+	}
+	exit(exitstatus);
 	/*NOTREACHED*/
 }
 	
@@ -227,7 +233,7 @@ parse_args(argc, argv)
 				perror(Filename);
 				exit(ERROR_EXIT);
 			}
-			if (swap_uids() < OK) {
+			if (swap_uids_back() < OK) {
 				perror("swapping uids back");
 				exit(ERROR_EXIT);
 			}
@@ -473,7 +479,8 @@ edit_cmd() {
 			ProgramName, Filename);
 		goto done;
 	default:
-		fprintf(stderr, "%s: panic: bad switch() in replace_cmd()\n");
+		fprintf(stderr, "%s: panic: bad switch() in replace_cmd()\n",
+			ProgramName);
 		goto fatal;
 	}
  remove:
@@ -517,7 +524,6 @@ replace_cmd() {
 	Set_LineNum(1)
 	while (EOF != (ch = get_char(NewCrontab)))
 		putc(ch, tmp);
-	ftruncate(fileno(tmp), ftell(tmp));
 	fflush(tmp);  rewind(tmp);
 
 	if (ferror(tmp)) {
@@ -574,7 +580,7 @@ replace_cmd() {
 	if (chmod(tn, 0600) < OK)
 #endif
 	{
-		perror("chown");
+		perror("chmod");
 		fclose(tmp);  unlink(tn);
 		return (-2);
 	}
diff --git a/database.c b/database.c
index 879aaaa..67b71a0 100644
--- a/database.c
+++ b/database.c
@@ -189,8 +189,8 @@ unlink_user(db, u)
 
 user *
 find_user(db, name)
-	cron_db	*db;
-	char	*name;
+	cron_db		*db;
+	const char	*name;
 {
 	char	*env_get();
 	user	*u;
diff --git a/do_command.c b/do_command.c
index 11e157a..b8e32df 100644
--- a/do_command.c
+++ b/do_command.c
@@ -99,10 +99,10 @@ child_process(e, u)
 #ifdef USE_SIGCHLD
 	/* our parent is watching for our death by catching SIGCHLD.  we
 	 * do not care to watch for our children's deaths this way -- we
-	 * use wait() explictly.  so we have to disable the signal (which
+	 * use wait() explictly.  so we have to reset the signal (which
 	 * was inherited from the parent).
 	 */
-	(void) signal(SIGCHLD, SIG_IGN);
+	(void) signal(SIGCHLD, SIG_DFL);
 #else
 	/* on system-V systems, we are ignoring SIGCLD.  we have to stop
 	 * ignoring it now or the wait() in cron_pclose() won't work.
@@ -146,13 +146,13 @@ child_process(e, u)
 
 	/* fork again, this time so we can exec the user's command.
 	 */
-	switch (vfork()) {
+	switch (fork()) {
 	case -1:
-		log_it("CRON",getpid(),"error","can't vfork");
+		log_it("CRON",getpid(),"error","can't fork");
 		exit(ERROR_EXIT);
 		/*NOTREACHED*/
 	case 0:
-		Debug(DPROC, ("[%d] grandchild process Vfork()'ed\n",
+		Debug(DPROC, ("[%d] grandchild process fork()'ed\n",
 			      getpid()))
 
 		/* write a log message.  we've waited this long to do it
@@ -169,9 +169,7 @@ child_process(e, u)
 
 		/* that's the last thing we'll log.  close the log files.
 		 */
-#ifdef SYSLOG
-		closelog();
-#endif
+		log_close();
 
 		/* get new pgrp, void tty, etc.
 		 */
@@ -189,9 +187,9 @@ child_process(e, u)
 		/* grandchild process.  make std{in,out} be the ends of
 		 * pipes opened by our daddy; make stderr go to stdout.
 		 */
-		close(STDIN);	dup2(stdin_pipe[READ_PIPE], STDIN);
-		close(STDOUT);	dup2(stdout_pipe[WRITE_PIPE], STDOUT);
-		close(STDERR);	dup2(STDOUT, STDERR);
+		dup2(stdin_pipe[READ_PIPE], STDIN);
+		dup2(stdout_pipe[WRITE_PIPE], STDOUT);
+		dup2(STDOUT, STDERR);
 
 		/* close the pipes we just dup'ed.  The resources will remain.
 		 */
@@ -331,7 +329,7 @@ child_process(e, u)
 		register int	ch = getc(in);
 
 		if (ch != EOF) {
-			register FILE	*mail;
+			register FILE	*mail = NULL;
 			register int	bytes = 1;
 			int		status = 0;
 
diff --git a/env.c b/env.c
index 7eb53fa..b788e75 100644
--- a/env.c
+++ b/env.c
@@ -39,6 +39,9 @@ env_free(envp)
 {
 	char	**p;
 
+	if(!envp)
+		return;
+
 	for (p = envp;  *p;  p++)
 		free(*p);
 	free(envp);
@@ -168,7 +171,7 @@ env_get(name, envp)
 	register int	len = strlen(name);
 	register char	*p, *q;
 
-	while (p = *envp++) {
+	while ((p = *envp++) != NULL) {
 		if (!(q = strchr(p, '=')))
 			continue;
 		if ((q - p) == len && !strncmp(p, name, len))
diff --git a/misc.c b/misc.c
index c912ffb..c03f25f 100644
--- a/misc.c
+++ b/misc.c
@@ -44,6 +44,10 @@ static char rcsid[] = "$Id: misc.c,v 2.9 1994/01/15 20:43:43 vixie Exp $";
 #define LOG_CRON LOG_DAEMON
 #endif
 
+#if defined(SYSLOG)
+	static int		syslog_open = 0;
+#endif
+
 
 static int		LogFD = ERR;
 
@@ -468,10 +472,6 @@ log_it(username, xpid, event, detail)
 	register struct tm	*t = localtime(&now);
 #endif /*LOG_FILE*/
 
-#if defined(SYSLOG)
-	static int		syslog_open = 0;
-#endif
-
 #if defined(LOG_FILE)
 	/* we assume that MAX_TEMPSTR will hold the date, time, &punctuation.
 	 */
@@ -514,11 +514,7 @@ log_it(username, xpid, event, detail)
 
 #if defined(SYSLOG)
 	if (!syslog_open) {
-		/* we don't use LOG_PID since the pid passed to us by
-		 * our client may not be our own.  therefore we want to
-		 * print the pid ourselves.
-		 */
-# ifdef LOG_DAEMON
+# ifdef LOG_CRON
 		openlog(ProgramName, LOG_PID, LOG_CRON);
 # else
 		openlog(ProgramName, LOG_PID);
@@ -526,14 +522,14 @@ log_it(username, xpid, event, detail)
 		syslog_open = TRUE;		/* assume openlog success */
 	}
 
-	syslog(LOG_INFO, "(%s) %s (%s)\n", username, event, detail);
+	syslog(LOG_INFO, "(%s) %s (%s)", username, event, detail);
 
 #endif /*SYSLOG*/
 
 #if DEBUGGING
 	if (DebugFlags) {
 		fprintf(stderr, "log_it: (%s %d) %s (%s)\n",
-			username, pid, event, detail);
+			username, xpid, event, detail);
 	}
 #endif
 }
@@ -541,10 +537,16 @@ log_it(username, xpid, event, detail)
 
 void
 log_close() {
+#if defined(LOG_FILE)
 	if (LogFD != ERR) {
 		close(LogFD);
 		LogFD = ERR;
 	}
+#endif
+#if defined(SYSLOG)
+	closelog();
+	syslog_open = FALSE;
+#endif
 }
 
 
@@ -654,7 +656,7 @@ arpadate(clock)
 #endif /*MAIL_DATE*/
 
 
-#ifdef HAVE_SAVED_SUIDS
+#ifdef HAVE_SAVED_UIDS
 static int save_euid;
 int swap_uids() { save_euid = geteuid(); return seteuid(getuid()); }
 int swap_uids_back() { return seteuid(save_euid); }
diff --git a/popen.c b/popen.c
index d6c2c75..ba59b97 100644
--- a/popen.c
+++ b/popen.c
@@ -58,7 +58,7 @@ cron_popen(program, type)
 	extern char **glob(), **copyblk();
 #endif
 
-	if (*type != 'r' && *type != 'w' || type[1])
+	if ((*type != 'r' && *type != 'w') || type[1])
 		return(NULL);
 
 	if (!pids) {
@@ -93,7 +93,7 @@ cron_popen(program, type)
 #endif
 
 	iop = NULL;
-	switch(pid = vfork()) {
+	switch(pid = fork()) {
 	case -1:			/* error */
 		(void)close(pdes[0]);
 		(void)close(pdes[1]);
diff --git a/user.c b/user.c
index 9672dd5..e010f74 100644
--- a/user.c
+++ b/user.c
@@ -75,6 +75,7 @@ load_user(crontab_fd, pw, name)
 	/*
 	 * load the crontab
 	 */
+	Set_LineNum(1)
 	while ((status = load_env(envstr, file)) >= OK) {
 		switch (status) {
 		case ERR: