Fix autoExecute() skipping updates

AutoExecute fetches a row from the table prior to performing an insert
or update. When $forceUpdate is false, only modified columns should be
updated. However, the WHERE clause was not being used when fetching the
row, so the comparison was always made against an arbitrary row, causing
differences to be detected or missed by chance.

This change makes use of the $where parameter when fetching the row from
the table, making the comparison work as intended.

Fixes #1146

2 files changed, 32 insertions, 3 deletions

diff --git a/adodb.inc.php b/adodb.inc.php
index f995eeb0..6726d042 100644
--- a/adodb.inc.php
+++ b/adodb.inc.php
@@ -2665,15 +2665,16 @@ if (!defined('_ADODB_LAYER')) {
 		}
 
 		$sql = "SELECT * FROM $table";
+		if (!empty($where)) {
+			$sql .= " WHERE $where";
+		}
+
 		$rs = $this->SelectLimit($sql, 1);
 		if (!$rs) {
 			return false; // table does not exist
 		}
 
 		$rs->tableName = $table;
-		if (!empty($where)) {
-			$sql .= " WHERE $where";
-		}
 		$rs->sql = $sql;
 
 		switch($mode) {
diff --git a/tests/test-autoexecute-update.php b/tests/test-autoexecute-update.php
new file mode 100644
index 00000000..4ac8b619
--- /dev/null
+++ b/tests/test-autoexecute-update.php
@@ -0,0 +1,28 @@
+<?php
+
+require __DIR__ . "/../adodb.inc.php";
+
+$db = NewADOConnection("sqlite3");
+$db->Connect(":memory:");
+
+$db->Execute("CREATE TABLE users(id primary key, name, year_of_birth)");
+$db->Execute("INSERT INTO users VALUES (1, 'John', 2000)");
+$db->Execute("INSERT INTO users VALUES (2, 'Jane', 1981)");
+
+$new_value = 2000;
+
+$db->autoExecute(
+    table: "users",
+    fields_values: ["year_of_birth" => $new_value],
+    mode: "UPDATE",
+    where: "id = 2",
+    forceUpdate: false,
+);
+
+$updated_value = $db->GetOne("SELECT year_of_birth FROM users WHERE id = 2");
+
+if ($updated_value != $new_value) {
+    die("ERROR: updated_value $updated_value != new_value $new_value");
+}
+
+echo "Finished.\n";