Fix GH-8121: SplFileObject - seek and key with csv file inconsistent

First, we must not free the current line before we call
`spl_filesystem_file_read_csv()`, because then the `current_line` will
not be properly updated.  Since the EOF check is superfluous here, we
move that part of the code to the branch for subtypes.  This issue has
been introduced by the fix for bug 75917.

Second, we only must increase the `current_line` if we're not reading
ahead.  This issue has been introduced by the fix for bug 62004.

Closes GH-8138.

NEWS

@@ -13,6 +13,10 @@ PHP                                                                        NEWS
 - Pcntl:
   . Fixed bug GH-8142 (Compilation error on cygwin). (David Carlier)
 
+- SPL:
+  . Fixed bug GH-8121 (SplFileObject - seek and key with csv file inconsistent).
+    (cmb)
+
 - Standard:
   . Fixed bug GH-8048 (Force macOS to use statfs). (risner)
 

ext/spl/spl_directory.c

@@ -1938,7 +1938,11 @@ static int spl_filesystem_file_read_line_ex(zval * this_ptr, spl_filesystem_obje
 	zval retval;
 
 	/* 1) use fgetcsv? 2) overloaded call the function, 3) do it directly */
-	if (SPL_HAS_FLAG(intern->flags, SPL_FILE_OBJECT_READ_CSV) || intern->u.file.func_getCurr->common.scope != spl_ce_SplFileObject) {
+	if (SPL_HAS_FLAG(intern->flags, SPL_FILE_OBJECT_READ_CSV)) {
+		return spl_filesystem_file_read_csv(intern, intern->u.file.delimiter, intern->u.file.enclosure, intern->u.file.escape, NULL);
+	}
+	if (intern->u.file.func_getCurr->common.scope != spl_ce_SplFileObject) {
+		zend_execute_data *execute_data = EG(current_execute_data);
 		spl_filesystem_file_free_line(intern);
 
 		if (php_stream_eof(intern->u.file.stream)) {
@@ -1947,12 +1951,7 @@ static int spl_filesystem_file_read_line_ex(zval * this_ptr, spl_filesystem_obje
 			}
 			return FAILURE;
 		}
-		if (SPL_HAS_FLAG(intern->flags, SPL_FILE_OBJECT_READ_CSV)) {
-			return spl_filesystem_file_read_csv(intern, intern->u.file.delimiter, intern->u.file.enclosure, intern->u.file.escape, NULL);
-		} else {
-			zend_execute_data *execute_data = EG(current_execute_data);
-			zend_call_method_with_0_params(Z_OBJ_P(this_ptr), Z_OBJCE_P(ZEND_THIS), &intern->u.file.func_getCurr, "getCurrentLine", &retval);
-		}
+		zend_call_method_with_0_params(Z_OBJ_P(this_ptr), Z_OBJCE_P(ZEND_THIS), &intern->u.file.func_getCurr, "getCurrentLine", &retval);
 		if (!Z_ISUNDEF(retval)) {
 			if (intern->u.file.current_line || !Z_ISUNDEF(intern->u.file.current_zval)) {
 				intern->u.file.current_line_num++;
@@ -2739,8 +2738,8 @@ PHP_METHOD(SplFileObject, seek)
 		}
 	}
 	if (line_pos > 0) {
-		intern->u.file.current_line_num++;
 		if (!SPL_HAS_FLAG(intern->flags, SPL_FILE_OBJECT_READ_AHEAD)) {
+			intern->u.file.current_line_num++;
 			spl_filesystem_file_free_line(intern);
 		}
 	}

ext/spl/tests/gh8121.csv

@@ -0,0 +1,5 @@
+id,status,on_sale,brand,name,link,meta_title,meta_desc,description
+1,2,15,Samsung,M21,samsung-m21,Samsung M21,Samsung M21,Samsung M21
+2,2,15,Samsung,M32,samsung-m32,Samsung M32,Samsung M32,Samsung M32
+3,2,15,Samsung,M21,samsung-m21,Samsung M21,Samsung M21,Samsung M21
+4,2,15,Samsung,M32,samsung-m32,Samsung M32,Samsung M32,Samsung M32

ext/spl/tests/gh8121.phpt

@@ -0,0 +1,39 @@
+--TEST--
+GH-8121 (SplFileObject - seek and key with csv file inconsistent)
+--FILE--
+<?php
+$flagss = [
+    SplFileObject::READ_AHEAD | SplFileObject::READ_CSV | SplFileObject::SKIP_EMPTY | SplFileObject::DROP_NEW_LINE,
+    SplFileObject::READ_AHEAD |                           SplFileObject::SKIP_EMPTY | SplFileObject::DROP_NEW_LINE,
+                                                          SplFileObject::SKIP_EMPTY | SplFileObject::DROP_NEW_LINE,
+];
+foreach ($flagss as $flags) {
+    $file = new SplFileObject(__DIR__ . "/gh8121.csv", "r");
+    echo "flags: $flags\n";
+    $file->setFlags($flags);
+    $file->seek(0);
+    var_dump($file->key());
+    $file->seek(1);
+    var_dump($file->key());
+    $file->seek(2);
+    var_dump($file->key());
+    $file->seek(3);
+    var_dump($file->key());
+}
+?>
+--EXPECT--
+flags: 15
+int(0)
+int(1)
+int(2)
+int(3)
+flags: 7
+int(0)
+int(1)
+int(2)
+int(3)
+flags: 5
+int(0)
+int(1)
+int(2)
+int(3)