From ecf902895d9f85d989532058492bc68326a9439f Mon Sep 17 00:00:00 2001
From: Tristan Partin <tristan@partin.io>
Date: Thu, 30 Jul 2026 08:23:25 +0000
Subject: [PATCH v1 2/5] Fix integer parsing in manifest parser for portability

strtoul() can set two different values for errno: EINVAL and ERANGE.
Quoting the man page for EINVAL:

> The value of base is not supported or no conversion could be performed
> (the last feature is not portable across all platforms).

Emphasis on the portion in parentheses.

Take the following example:

    strtoul("", &endptr, 10);

On glibc, the output value is 0, errno *is not* set, and endptr points
to the empty string.

On Apple libc, the output value is 0, errno *is* set to EINVAL, and
endptr points to the empty string.

In this case, when we try to parse an empty string, glibc treats that as
a 0, and Apple libc correctly treats it as an error.

Signed-off-by: Tristan Partin <tristan@partin.io>
---
 src/bin/pg_verifybackup/t/005_bad_manifest.pl | 16 ++++++++++++++++
 src/common/parse_manifest.c                   |  6 +++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/bin/pg_verifybackup/t/005_bad_manifest.pl b/src/bin/pg_verifybackup/t/005_bad_manifest.pl
index 0413fea02c3..bc9fe4a79d7 100644
--- a/src/bin/pg_verifybackup/t/005_bad_manifest.pl
+++ b/src/bin/pg_verifybackup/t/005_bad_manifest.pl
@@ -39,6 +39,10 @@
 {"PostgreSQL-Backup-Manifest-Version": 9876599}
 EOM
 
+test_parse_error('system identifier in manifest not an integer', <<EOM);
+{"PostgreSQL-Backup-Manifest-Version": 1, "System-Identifier": ""}
+EOM
+
 test_parse_error('unexpected scalar', <<EOM);
 {"PostgreSQL-Backup-Manifest-Version": 1, "Files": true}
 EOM
@@ -79,6 +83,12 @@
 ]}
 EOM
 
+test_parse_error('file size is not an integer', <<EOM);
+{"PostgreSQL-Backup-Manifest-Version": 1, "Files": [
+    {"Path": "x", "Size": ""}
+]}
+EOM
+
 test_parse_error('could not decode file name', <<EOM);
 {"PostgreSQL-Backup-Manifest-Version": 1, "Files": [
     {"Encoded-Path": "123", "Size": 0}
@@ -146,6 +156,12 @@
 ]}
 EOM
 
+test_parse_error('timeline is not an integer', <<EOM);
+{"PostgreSQL-Backup-Manifest-Version": 1, "WAL-Ranges": [
+    {"Timeline": "", "Start-LSN": "0/0", "End-LSN": "0/0"}
+]}
+EOM
+
 test_parse_error('could not parse start LSN', <<EOM);
 {"PostgreSQL-Backup-Manifest-Version": 1, "WAL-Ranges": [
     {"Timeline": 1, "Start-LSN": "oops", "End-LSN": "0/0"}
diff --git a/src/common/parse_manifest.c b/src/common/parse_manifest.c
index 5065c9bf39c..337cae535f4 100644
--- a/src/common/parse_manifest.c
+++ b/src/common/parse_manifest.c
@@ -631,7 +631,7 @@ json_manifest_finalize_system_identifier(JsonManifestParseState *parse)
 
 	/* Parse system identifier. */
 	system_identifier = strtou64(parse->manifest_system_identifier, &ep, 10);
-	if (*ep)
+	if (ep == parse->manifest_system_identifier || *ep)
 		json_manifest_parse_failure(parse->context,
 									"system identifier in manifest not an integer");
 
@@ -688,7 +688,7 @@ json_manifest_finalize_file(JsonManifestParseState *parse)
 
 	/* Parse size. */
 	size = strtou64(parse->size, &ep, 10);
-	if (*ep)
+	if (ep == parse->size || *ep)
 		json_manifest_parse_failure(parse->context,
 									"file size is not an integer");
 
@@ -766,7 +766,7 @@ json_manifest_finalize_wal_range(JsonManifestParseState *parse)
 
 	/* Parse timeline. */
 	tli = strtoul(parse->timeline, &ep, 10);
-	if (*ep)
+	if (ep == parse->timeline || *ep)
 		json_manifest_parse_failure(parse->context,
 									"timeline is not an integer");
 	if (!parse_xlogrecptr(&start_lsn, parse->start_lsn))
-- 
Tristan Partin
https://tristan.partin.io