r16230: Fix Klocwork #861 and others. localtime and asctime

can return NULL. Ensure we check all returns correctly.
Jeremy.
(This used to be commit 6c61dc8ed6d84f310ef391fb7700e93ef42c4afc)

2 files changed, 83 insertions, 56 deletions

diff --git a/source3/lib/replace.c b/source3/lib/replace.c
index 9ef3503d39..19b37af938 100644
--- a/source3/lib/replace.c
+++ b/source3/lib/replace.c
@@ -95,49 +95,50 @@ Corrections by richard.kettlewell@kewill.com
 #define  YEAR    365*DAY
  time_t mktime(struct tm *t)
 {
-  struct tm       *u;
-  time_t  epoch = 0;
-  int n;
-  int             mon [] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
-  y, m, i;
-
-  if(t->tm_year < 70)
-    return((time_t)-1);
-
-  n = t->tm_year + 1900 - 1;
-  epoch = (t->tm_year - 70) * YEAR + 
-    ((n / 4 - n / 100 + n / 400) - (1969 / 4 - 1969 / 100 + 1969 / 400)) * DAY;
-
-  y = t->tm_year + 1900;
-  m = 0;
-
-  for(i = 0; i < t->tm_mon; i++) {
-    epoch += mon [m] * DAY;
-    if(m == 1 && y % 4 == 0 && (y % 100 != 0 || y % 400 == 0))
-      epoch += DAY;
+	struct tm       *u;
+	time_t  epoch = 0;
+	int n;
+	int             mon [] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+	y, m, i;
+
+	if(t->tm_year < 70) {
+		return((time_t)-1);
+	}
+
+	n = t->tm_year + 1900 - 1;
+	epoch = (t->tm_year - 70) * YEAR + ((n / 4 - n / 100 + n / 400) - (1969 / 4 - 1969 / 100 + 1969 / 400)) * DAY;
+
+	y = t->tm_year + 1900;
+	m = 0;
+
+	for(i = 0; i < t->tm_mon; i++) {
+		epoch += mon [m] * DAY;
+		if(m == 1 && y % 4 == 0 && (y % 100 != 0 || y % 400 == 0)) {
+			epoch += DAY;
+		}
     
-    if(++m > 11) {
-      m = 0;
-      y++;
-    }
-  }
-
-  epoch += (t->tm_mday - 1) * DAY;
-  epoch += t->tm_hour * HOUR + t->tm_min * MINUTE + t->tm_sec;
+		if(++m > 11) {
+			m = 0;
+			y++;
+		}
+	}
+
+	epoch += (t->tm_mday - 1) * DAY;
+	epoch += t->tm_hour * HOUR + t->tm_min * MINUTE + t->tm_sec;
   
-  if((u = localtime(&epoch)) != NULL) {
-    t->tm_sec = u->tm_sec;
-    t->tm_min = u->tm_min;
-    t->tm_hour = u->tm_hour;
-    t->tm_mday = u->tm_mday;
-    t->tm_mon = u->tm_mon;
-    t->tm_year = u->tm_year;
-    t->tm_wday = u->tm_wday;
-    t->tm_yday = u->tm_yday;
-    t->tm_isdst = u->tm_isdst;
-  }
-
-  return(epoch);
+	if((u = localtime(&epoch)) != NULL) {
+		t->tm_sec = u->tm_sec;
+		t->tm_min = u->tm_min;
+		t->tm_hour = u->tm_hour;
+		t->tm_mday = u->tm_mday;
+		t->tm_mon = u->tm_mon;
+		t->tm_year = u->tm_year;
+		t->tm_wday = u->tm_wday;
+		t->tm_yday = u->tm_yday;
+		t->tm_isdst = u->tm_isdst;
+	}
+
+	return(epoch);
 }
 #endif /* !HAVE_MKTIME */
 
@@ -147,15 +148,15 @@ Corrections by richard.kettlewell@kewill.com
 /* Rename a file. (from libiberty in GNU binutils)  */
  int rename(const char *zfrom, const char *zto)
 {
-  if (link (zfrom, zto) < 0)
-    {
-      if (errno != EEXIST)
-	return -1;
-      if (unlink (zto) < 0
-	  || link (zfrom, zto) < 0)
-	return -1;
-    }
-  return unlink (zfrom);
+	if (link (zfrom, zto) < 0) {
+		if (errno != EEXIST) {
+			return -1;
+		}
+		if (unlink (zto) < 0 || link (zfrom, zto) < 0) {
+			return -1;
+		}
+	}
+	return unlink (zfrom);
 }
 #endif /* HAVE_RENAME */
 
diff --git a/source3/lib/time.c b/source3/lib/time.c
index f8a1538910..9a539d415e 100644
--- a/source3/lib/time.c
+++ b/source3/lib/time.c
@@ -615,16 +615,19 @@ char *http_timestring(time_t t)
 	static fstring buf;
 	struct tm *tm = localtime(&t);
 
-	if (!tm)
+	if (!tm) {
 		slprintf(buf,sizeof(buf)-1,"%ld seconds since the Epoch",(long)t);
-	else
+	} else {
 #ifndef HAVE_STRFTIME
-		fstrcpy(buf, asctime(tm));
-	if(buf[strlen(buf)-1] == '\n')
+		const char *asct = asctime(tm);
+		fstrcpy(buf, asct ? asct : "unknown");
+	}
+	if(buf[strlen(buf)-1] == '\n') {
 		buf[strlen(buf)-1] = 0;
 #else /* !HAVE_STRFTIME */
 		strftime(buf, sizeof(buf)-1, "%a, %d %b %Y %H:%M:%S %Z", tm);
 #endif /* !HAVE_STRFTIME */
+	}
 	return buf;
 }
 
@@ -672,13 +675,15 @@ char *timestring(BOOL hires)
 		}
 #else
 		if (hires) {
+			const char *asct = asctime(tm);
 			slprintf(TimeBuf, 
 				 sizeof(TimeBuf)-1, 
 				 "%s.%06ld", 
-				 asctime(tm), 
+				 asct ? asct : "unknown", 
 				 (long)tp.tv_usec);
 		} else {
-			fstrcpy(TimeBuf, asctime(tm));
+			const char *asct = asctime(tm);
+			fstrcpy(TimeBuf, asct ? asct : "unknown");
 		}
 #endif
 	}
@@ -1050,3 +1055,24 @@ struct timespec get_create_timespec(SMB_STRUCT_STAT *st,BOOL fake_dirs)
 	return ret;
 }
 #endif
+
+/****************************************************************************
+ Utility function that always returns a const string even if localtime
+ and asctime fail.
+****************************************************************************/
+
+const char *time_to_asc(const time_t *t)
+{
+	const char *asct;
+	struct tm *lt = localtime(t);
+
+	if (!lt) {
+		return "unknown time";
+	}
+
+	asct = asctime(lt);
+	if (!asct) {
+		return "unknown time";
+	}
+	return asct;
+}