Enable erase_empty_line in ext/readline (#14526)

This wasn't activated due to inconsistent availability over the
editline/readline versions and variants. This now checks whether the
rl_erase_empty_line variable is available in library headers and enables
it based on that. On Windows this is for now still disabled due to
wineditline library, which doesn't have this yet.

Documentation already mentions the erase_empty_line setting:
https://www.php.net/manual/en/function.readline-info.php

ext/readline/config.m4

@@ -75,6 +75,11 @@ if test "$PHP_READLINE" && test "$PHP_READLINE" != "no"; then
     -L$READLINE_DIR/$PHP_LIBDIR $PHP_READLINE_LIBS
   ])
 
+  AC_CHECK_DECL([rl_erase_empty_line],
+    [AC_DEFINE([HAVE_ERASE_EMPTY_LINE], [1],
+      [Define to 1 if readline library has rl_erase_empty_line variable.])],,
+    [#include <readline/readline.h>])
+
   AC_DEFINE(HAVE_HISTORY_LIST, 1, [ ])
   AC_DEFINE(HAVE_LIBREADLINE, 1, [ ])
 
@@ -133,6 +138,11 @@ elif test "$PHP_LIBEDIT" != "no"; then
     $READLINE_SHARED_LIBADD
   ])
 
+  AC_CHECK_DECL([rl_erase_empty_line],
+    [AC_DEFINE([HAVE_ERASE_EMPTY_LINE], [1],
+      [Define to 1 if edit library has rl_erase_empty_line variable.])],,
+    [#include <editline/readline.h>])
+
   AC_DEFINE(HAVE_LIBEDIT, 1, [ ])
 fi
 

ext/readline/readline.c

@@ -171,7 +171,7 @@ PHP_FUNCTION(readline_info)
 				: ZSTR_CHAR(rl_completion_append_character));
 		add_assoc_bool(return_value,"completion_suppress_append",rl_completion_suppress_append);
 #endif
-#if HAVE_ERASE_EMPTY_LINE
+#ifdef HAVE_ERASE_EMPTY_LINE
 		add_assoc_long(return_value,"erase_empty_line",rl_erase_empty_line);
 #endif
 #ifndef PHP_WIN32
@@ -235,7 +235,7 @@ PHP_FUNCTION(readline_info)
 			RETVAL_INTERNED_STR(
 				oldval == 0 ? ZSTR_EMPTY_ALLOC() : ZSTR_CHAR(oldval));
 #endif
-#if HAVE_ERASE_EMPTY_LINE
+#ifdef HAVE_ERASE_EMPTY_LINE
 		} else if (zend_string_equals_literal_ci(what, "erase_empty_line")) {
 			oldval = rl_erase_empty_line;
 			if (value) {

ext/readline/tests/libedit_info_001.phpt

@@ -24,13 +24,13 @@ var_dump(readline_info('attempted_completion_over'));
 
 ?>
 --EXPECTF--
-array(6) {
+array(%d) {
   ["line_buffer"]=>
   string(0) ""
   ["point"]=>
   int(0)
   ["end"]=>
-  int(0)
+  int(0)%A
   ["library_version"]=>
   string(%d) "%s"
   ["readline_name"]=>

ext/readline/tests/readline_info_001.phpt

@@ -25,7 +25,7 @@ var_dump(readline_info('completion_suppress_append'));
 
 ?>
 --EXPECTF--
-array(13) {
+array(%d) {
   ["line_buffer"]=>
   string(0) ""
   ["point"]=>
@@ -45,7 +45,7 @@ array(13) {
   ["completion_append_character"]=>
   string(1) " "
   ["completion_suppress_append"]=>
-  bool(false)
+  bool(false)%A
   ["library_version"]=>
   string(%d) "%s"
   ["readline_name"]=>