From bd5200dfb2a3dff0cf58daf9a3a6313a2dd2f89b Mon Sep 17 00:00:00 2001
From: Ryan Cramer <ryan@processwire.com>
Date: Sun, 5 Jan 2025 10:54:17 -0500
Subject: [PATCH] Fix issue processwire/processwire-issues#1966

---
 wire/core/Field.php  | 5 ++++-
 wire/core/Fields.php | 8 +++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/wire/core/Field.php b/wire/core/Field.php
index 5f8978e6..198d53e5 100644
--- a/wire/core/Field.php
+++ b/wire/core/Field.php
@@ -1248,7 +1248,9 @@ class Field extends WireData implements Saveable, Exportable {
 			$table = $this->setTable;
 		} else {
 			$name = $this->settings['name'];
-			if(!strlen($name)) throw new WireException("Field 'name' is required");
+			$length = strlen($name);
+			if(!$length) throw new WireException("Field 'name' is required");
+			if($length > 58) $name = substr($name, 0, 58); // 'field_' + 58 = 64 max
 			$table = self::tablePrefix . $name;
 		}
 		if(self::$lowercaseTables) $table = strtolower($table); 
@@ -1265,6 +1267,7 @@ class Field extends WireData implements Saveable, Exportable {
 	 */
 	public function setTable($table = null) {
 		$table = empty($table) ? '' : $this->wire()->sanitizer->fieldName($table);
+		if(strlen($table) > 64) $table = substr($table, 0, 64);
 		$this->setTable = $table;
 	}
 
diff --git a/wire/core/Fields.php b/wire/core/Fields.php
index 823f2dbf..0b5bcad0 100644
--- a/wire/core/Fields.php
+++ b/wire/core/Fields.php
@@ -388,12 +388,14 @@ class Fields extends WireSaveableItems {
 			// even if only the case has changed. 
 			$schema = $item->type->getDatabaseSchema($item);
 			if(!empty($schema)) {
-				foreach(array($table, "tmp_$table") as $t) {
+				list(,$tmpTable) = explode(Field::tablePrefix, $table, 2);
+				$tmpTable = "tempf_$tmpTable";
+				foreach(array($table, $tmpTable) as $t) {
 					if(!$database->tableExists($t)) continue;
 					throw new WireException("Cannot rename to '$item->name' because table `$table` already exists");
 				}
-				$database->exec("RENAME TABLE `$prevTable` TO `tmp_$table`"); // QA
-				$database->exec("RENAME TABLE `tmp_$table` TO `$table`"); // QA
+				$database->exec("RENAME TABLE `$prevTable` TO `$tmpTable`"); // QA
+				$database->exec("RENAME TABLE `$tmpTable` TO `$table`"); // QA
 			}
 			$item->prevTable = '';
 		}