In-depth robustness.

Reported by: clang static analyzer (clang-8)

3 files changed, 6 insertions, 5 deletions

diff --git a/driver.c b/driver.c
index 6176bcb9..74e1b28a 100644
--- a/driver.c
+++ b/driver.c
@@ -542,8 +542,9 @@ static int fetch_messages(int mailserver_socket, struct query *ctl,
 	    lastnum = num + fetchsizelimit - 1;
 	    if (lastnum > count)
 		lastnum = count;
-	    for (i = 0; i < fetchsizelimit; i++)
-		(*msgsizes)[i] = 0;
+	    if (*msgsizes)
+		for (i = 0; i < fetchsizelimit; i++)
+		    (*msgsizes)[i] = 0;
 
 	    stage = STAGE_GETSIZES;
 	    err = (ctl->server.base_protocol->getpartialsizes)(mailserver_socket, num, lastnum, *msgsizes);
diff --git a/report.c b/report.c
index 5d9abb73..1466802a 100644
--- a/report.c
+++ b/report.c
@@ -362,7 +362,7 @@ report_at_line (FILE *errfp, errnum, file_name, line_number, message, va_alist)
 	static unsigned int old_line_number;
 
 	if (old_line_number == line_number &&
-	    (file_name == old_file_name || !strcmp (old_file_name, file_name)))
+	    (file_name == old_file_name || (old_file_name != NULL && 0 == strcmp (old_file_name, file_name))))
 	    /* Simply return and print nothing.  */
 	    return;
 
diff --git a/sink.c b/sink.c
index e8dd8355..164c36d8 100644
--- a/sink.c
+++ b/sink.c
@@ -1189,14 +1189,14 @@ static int open_mda_sink(struct query *ctl, struct msgblk *msg,
 	    ** the worst case (end of string) sp[1] == '\0' */
 	    if (sp[1] == 's' || sp[1] == 'T') {
 		*dp++ = '\'';
-		strcpy(dp, names);
+		if (names) strcpy(dp, names);
 		dp += nameslen;
 		*dp++ = '\'';
 		sp++;	/* position sp over [sT] */
 		dp--;	/* adjust dp */
 	    } else if (sp[1] == 'F') {
 		*dp++ = '\'';
-		strcpy(dp, from);
+		if (from) strcpy(dp, from);
 		dp += fromlen;
 		*dp++ = '\'';
 		sp++;	/* position sp over F */