From 95f862fdd82a99e30bbf2c43009ec9a51e416804 Mon Sep 17 00:00:00 2001
From: Tavian Barnes <tavianator@tavianator.com>
Date: Thu, 13 Feb 2020 16:30:05 -0500
Subject: parse: Handle 1969-12-31T23:59:59Z

mktime() returns -1 on error, but also for one second before the epoch.
Compare the input against localtime(-1) to distinguish those cases.
---
 parse.c                                | 27 ++++++++++++++-------------
 tests.sh                               |  6 ++++++
 tests/test_newermt_epoch_minus_one.out |  5 +++++
 util.c                                 | 27 ++++++++++++++++++++++++---
 util.h                                 | 20 +++++++++++++++++---
 5 files changed, 66 insertions(+), 19 deletions(-)
 create mode 100644 tests/test_newermt_epoch_minus_one.out

diff --git a/parse.c b/parse.c
index 6ffe8e7..ada0ec2 100644
--- a/parse.c
+++ b/parse.c
@@ -1129,9 +1129,9 @@ static struct expr *parse_daystart(struct parser_state *state, int arg1, int arg
 	tm.tm_min = 0;
 	tm.tm_sec = 0;
 
-	time_t time = mktime(&tm);
-	if (time == -1) {
-		perror("mktime()");
+	time_t time;
+	if (xmktime(&tm, &time) != 0) {
+		perror("xmktime()");
 		return NULL;
 	}
 
@@ -1753,23 +1753,20 @@ static int parse_timestamp(const struct parser_state *state, struct expr *expr)
 
 end:
 	if (local) {
-		expr->reftime.tv_sec = mktime(&tm);
-		if (expr->reftime.tv_sec == -1) {
-			perror("mktime()");
-			return -1;
+		if (xmktime(&tm, &expr->reftime.tv_sec) != 0) {
+			goto error;
 		}
 	} else {
-		expr->reftime.tv_sec = xtimegm(&tm);
-		if (expr->reftime.tv_sec == -1) {
-			perror("xtimegm()");
-			return -1;
+		if (xtimegm(&tm, &expr->reftime.tv_sec) != 0) {
+			goto error;
 		}
 
 		int offset = 60*tz_hour + tz_min;
 		if (tz_negative) {
-			offset = -offset;
+			expr->reftime.tv_sec -= offset;
+		} else {
+			expr->reftime.tv_sec += offset;
 		}
-		expr->reftime.tv_sec += offset;
 	}
 
 	expr->reftime.tv_nsec = 0;
@@ -1809,6 +1806,10 @@ invalid:
 	fprintf(stderr, "  - %04d-%02d-%02dT%02d:%02d:%02dZ\n", year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
 
 	return -1;
+
+error:
+	parse_error(state, "%s %s: Error parsing timestamp: %m.\n", expr->argv[0], expr->argv[1]);
+	return -1;
 }
 
 /**
diff --git a/tests.sh b/tests.sh
index 3893251..d1c5413 100755
--- a/tests.sh
+++ b/tests.sh
@@ -343,6 +343,7 @@ bsd_tests=(
 
     test_newerma
     test_newermt
+    test_newermt_epoch_minus_one
 
     test_nogroup
     test_nogroup_ulimit
@@ -492,6 +493,7 @@ gnu_tests=(
 
     test_newerma
     test_newermt
+    test_newermt_epoch_minus_one
 
     test_nogroup
     test_nogroup_ulimit
@@ -1364,6 +1366,10 @@ function test_newermt() {
     bfs_diff times -newermt 1991-12-14T00:01
 }
 
+function test_newermt_epoch_minus_one() {
+    bfs_diff times -newermt 1969-12-31T23:59:59Z
+}
+
 function test_size() {
     bfs_diff basic -type f -size 0
 }
diff --git a/tests/test_newermt_epoch_minus_one.out b/tests/test_newermt_epoch_minus_one.out
new file mode 100644
index 0000000..f7f63b0
--- /dev/null
+++ b/tests/test_newermt_epoch_minus_one.out
@@ -0,0 +1,5 @@
+times
+times/a
+times/b
+times/c
+times/l
diff --git a/util.c b/util.c
index 88f90aa..6af7d27 100644
--- a/util.c
+++ b/util.c
@@ -185,9 +185,30 @@ int xgmtime(const time_t *timep, struct tm *result) {
 	}
 }
 
-time_t xtimegm(struct tm *tm) {
+int xmktime(struct tm *tm, time_t *timep) {
+	*timep = mktime(tm);
+
+	if (*timep == -1) {
+		int error = errno;
+
+		struct tm tmp;
+		if (xlocaltime(timep, &tmp) != 0) {
+			return -1;
+		}
+
+		if (tm->tm_year != tmp.tm_year || tm->tm_yday != tmp.tm_yday
+		    || tm->tm_hour != tmp.tm_hour || tm->tm_min != tmp.tm_min || tm->tm_sec != tmp.tm_sec) {
+			errno = error;
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int xtimegm(struct tm *tm, time_t *timep) {
 	// Some man pages for timegm() recommend this as a portable approach
-	time_t ret = -1;
+	int ret = -1;
 	int error;
 
 	char *old_tz = getenv("TZ");
@@ -204,7 +225,7 @@ time_t xtimegm(struct tm *tm) {
 		goto fail;
 	}
 
-	ret = mktime(tm);
+	ret = xmktime(tm, timep);
 	error = errno;
 
 	if (old_tz) {
diff --git a/util.h b/util.h
index ef546d4..ae12703 100644
--- a/util.h
+++ b/util.h
@@ -181,15 +181,29 @@ int xlocaltime(const time_t *timep, struct tm *result);
  */
 int xgmtime(const time_t *timep, struct tm *result);
 
+/**
+ * mktime() wrapper that reports errors more reliably.
+ *
+ * @param[in,out] tm
+ *         The struct tm to convert.
+ * @param[out] timep
+ *         Where to store the result.
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int xmktime(struct tm *tm, time_t *timep);
+
 /**
  * A portable timegm(), the inverse of gmtime().
  *
- * @param tm
+ * @param[in,out] tm
  *         The struct tm to convert.
+ * @param[out] timep
+ *         Where to store the result.
  * @return
- *         The converted time on success, or -1 on failure.
+ *         0 on success, -1 on failure.
  */
-time_t xtimegm(struct tm *tm);
+int xtimegm(struct tm *tm, time_t *timep);
 
 /**
  * Format a mode like ls -l (e.g. -rw-r--r--).
-- 
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