From cdb7bd055950d0f56e70e77e7b1678a2d6fb25fc Mon Sep 17 00:00:00 2001
From: Rivers Zhang <hzhang320@bloomberg.net>
Date: Thu, 14 Aug 2025 15:28:44 -0400
Subject: [PATCH] Allowing omitting the "T" separator from a datetime string

Our customers have issue using spark to create a dataframe on a
datetime column, because spark interpolates the provided datetime
string, but drops the "T" separator when filling the range.

It seems that omitting the "T" character is fairly acceptable, and
ISO 8601 does allow it to be omitted in a few cases. This is a
very simple patch to allow it.

Signed-off-by: Rivers Zhang <hzhang320@bloomberg.net>
---
 db/types.c                                             | 10 ++++++++--
 tests/datetime.test/t25.expected                       |  6 ++++++
 tests/datetime.test/t25.sql                            |  8 ++++++++
 tests/udf.test/{nextval.req => nextval.0.req}          |  0
 .../{nextval.req.expected => nextval.0.req.expected}   |  0
 tests/udf.test/{nextval_1.req => nextval.1.req}        |  0
 .../{nextval_1.req.expected => nextval.1.req.expected} |  0
 tests/udf.test/runit                                   |  2 +-
 8 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 tests/datetime.test/t25.expected
 create mode 100644 tests/datetime.test/t25.sql
 rename tests/udf.test/{nextval.req => nextval.0.req} (100%)
 rename tests/udf.test/{nextval.req.expected => nextval.0.req.expected} (100%)
 rename tests/udf.test/{nextval_1.req => nextval.1.req} (100%)
 rename tests/udf.test/{nextval_1.req.expected => nextval.1.req.expected} (100%)

diff --git a/db/types.c b/db/types.c
index d3aa44668d..afef6190ee 100644
--- a/db/types.c
+++ b/db/types.c
@@ -7262,7 +7262,7 @@ static int _isISO8601(const char *str, int len)
     /* (month<1 || month>12)*/                                                 \
                                                                                \
     /*get day*/                                                                \
-    day = getInt(in, len, &offset, &ltoken, 1, 2, "-T", &skipped);             \
+    day = getInt(in, len, &offset, &ltoken, 1, 2, "-T ", &skipped);            \
     if (!ltoken)                                                               \
         return CONV_WRONG_MDAY;                                                \
     /*(day <1 || !is_valid_days(year, month, day))*/                           \
@@ -7307,8 +7307,14 @@ static int _isISO8601(const char *str, int len)
                 ss = 0;                                                        \
         } else                                                                 \
             mm = 0;                                                            \
-    } else                                                                     \
+    } else {                                                                   \
         hh = 0;                                                                \
+        /* Need to compensate if the last separator is a space */              \
+        /* Because we expect the timezone string to have a leading space */    \
+        /* See a few lines above for the same logic in parsing the fraction */ \
+        if (in[offset - 1] == ' ')                                             \
+            offset--; /*incremented afterwards*/                               \
+    }                                                                          \
                                                                                \
     /* fill in the blanks*/                                                    \
     out->tm.tm_year = year - 1900;                                             \
diff --git a/tests/datetime.test/t25.expected b/tests/datetime.test/t25.expected
new file mode 100644
index 0000000000..bebede3163
--- /dev/null
+++ b/tests/datetime.test/t25.expected
@@ -0,0 +1,6 @@
+(rows inserted=1)
+(rows inserted=1)
+(d="1970-01-01T000000.000 UTC")
+(d="1970-08-17T001501.000 UTC")
+(epoch=0)
+(epoch=19700101)
diff --git a/tests/datetime.test/t25.sql b/tests/datetime.test/t25.sql
new file mode 100644
index 0000000000..338cb96d75
--- /dev/null
+++ b/tests/datetime.test/t25.sql
@@ -0,0 +1,8 @@
+SET TIMEZONE UTC
+DROP TABLE IF EXISTS t25
+CREATE TABLE t25(d datetime)$$
+INSERT INTO t25 VALUES("1970-01-01 00:00:00 UTC")
+INSERT INTO t25 VALUES("19700101")
+SELECT d FROM t25
+SELECT CAST(d AS INT) AS epoch FROM t25
+DROP TABLE t25
diff --git a/tests/udf.test/nextval.req b/tests/udf.test/nextval.0.req
similarity index 100%
rename from tests/udf.test/nextval.req
rename to tests/udf.test/nextval.0.req
diff --git a/tests/udf.test/nextval.req.expected b/tests/udf.test/nextval.0.req.expected
similarity index 100%
rename from tests/udf.test/nextval.req.expected
rename to tests/udf.test/nextval.0.req.expected
diff --git a/tests/udf.test/nextval_1.req b/tests/udf.test/nextval.1.req
similarity index 100%
rename from tests/udf.test/nextval_1.req
rename to tests/udf.test/nextval.1.req
diff --git a/tests/udf.test/nextval_1.req.expected b/tests/udf.test/nextval.1.req.expected
similarity index 100%
rename from tests/udf.test/nextval_1.req.expected
rename to tests/udf.test/nextval.1.req.expected
diff --git a/tests/udf.test/runit b/tests/udf.test/runit
index 13eb2b19e9..a1b3baf411 100755
--- a/tests/udf.test/runit
+++ b/tests/udf.test/runit
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 set -x
-for t in *.req; do
+for t in `ls *.req | sort`; do
     cdb2sql --tabs --script --cdb2cfg ${CDB2_CONFIG} ${1} default - 2> ${t}.output 1>&2 < ${t}
     set -e
     diff ${t}.expected ${t}.output