Fix #77812: Interactive mode does not support PHP 7.3-style heredoc

As of PHP 7.3.0, the rules regarding the heredoc and nowdoc closing
identifier have been relaxed.  While formerly, the closing identifier
was required to be placed at the beginning of a line and to be
immediately followed by (a semicolon and) a line break, it may now be
preceeded by whitespace, and may be followed by any non-word character.
We adjust the recognition logic respectively.

NEWS

@@ -8,6 +8,8 @@ PHP                                                                        NEWS
     property). (Nikita)
   . Fixed bug #78441 (Parse error due to heredoc identifier followed by digit).
     (cmb)
+  . Fixed bug #77812 (Interactive mode does not support PHP 7.3-style heredoc).
+    (cmb, Nikita)
 
 - Intl:
   . Ensure IDNA2003 rules are used with idn_to_ascii() and idn_to_utf8()

ext/readline/readline_cli.c

@@ -347,11 +347,14 @@ static int cli_is_valid_code(char *code, size_t len, zend_string **prompt) /* {{
 				}
 				break;
 			case heredoc:
-				if (code[i - (heredoc_len + 1)] == '\n' && !strncmp(code + i - heredoc_len, heredoc_tag, heredoc_len) && code[i] == '\n') {
-					code_type = body;
-				} else if (code[i - (heredoc_len + 2)] == '\n' && !strncmp(code + i - heredoc_len - 1, heredoc_tag, heredoc_len) && code[i-1] == ';' && code[i] == '\n') {
+				if (!strncmp(code + i - heredoc_len + 1, heredoc_tag, heredoc_len)) {
+					unsigned char c = code[i + 1];
+					char *p = code + i - heredoc_len;
+
+					if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '_' || c >= 0x80) break;
+					while (*p == ' ' || *p == '\t') p--;
+					if (*p != '\n') break;
 					code_type = body;
-					valid_end = 1;
 				}
 				break;
 			case outside:

ext/readline/tests/bug77812-libedit.phpt

@@ -0,0 +1,34 @@
+--TEST--
+Bug #77812 (Interactive mode does not support PHP 7.3-style heredoc)
+--SKIPIF--
+<?php
+if (!extension_loaded('readline')) die('skip readline extension not available');
+if (READLINE_LIB !== "libedit") die('skip libedit only');
+if (!function_exists('proc_open')) die('skip proc_open() not available');
+?>
+--FILE--
+<?php
+$php = getenv('TEST_PHP_EXECUTABLE');
+$ini = getenv('TEST_PHP_EXTRA_ARGS');
+$descriptorspec = [['pipe', 'r'], STDOUT, STDERR];
+$proc = proc_open("$php $ini -a", $descriptorspec, $pipes);
+var_dump($proc);
+fwrite($pipes[0], "echo <<<FOO\n    bar\n    FOO;\n");
+fwrite($pipes[0], "print(<<<FOO\nxx\nFOO);\n");
+fwrite($pipes[0], "echo <<<FOO\n    xxx\n    FOO;\nFOO\n;\n");
+fwrite($pipes[0], "echo <<<FOO\nFOOL\nFOO\n,1;\n");
+fwrite($pipes[0], "echo <<<FOO\nFOO4\nFOO\n,2;\n");
+fclose($pipes[0]);
+proc_close($proc);
+?>
+--EXPECTF--
+resource(%d) of type (process)
+Interactive shell
+
+bar
+xx
+xxx
+
+Warning: Use of undefined constant FOO - assumed 'FOO' (this will throw an Error in a future version of PHP) in php shell code on line %d
+FOOL1
+FOO42

ext/readline/tests/bug77812-readline.phpt

@@ -0,0 +1,54 @@
+--TEST--
+Bug #77812 (Interactive mode does not support PHP 7.3-style heredoc)
+--SKIPIF--
+<?php
+if (!extension_loaded('readline')) die('skip readline extension not available');
+if (READLINE_LIB !== "readline") die('skip readline only');
+if (!function_exists('proc_open')) die('skip proc_open() not available');
+?>
+--FILE--
+<?php
+$php = getenv('TEST_PHP_EXECUTABLE');
+$ini = getenv('TEST_PHP_EXTRA_ARGS');
+$descriptorspec = [['pipe', 'r'], STDOUT, STDERR];
+$proc = proc_open("$php $ini -a", $descriptorspec, $pipes);
+var_dump($proc);
+fwrite($pipes[0], "echo <<<FOO\n    bar\n    FOO;\n");
+fwrite($pipes[0], "print(<<<FOO\nxx\nFOO);\n");
+fwrite($pipes[0], "echo <<<FOO\n    xxx\n    FOO;\nFOO\n;\n");
+fwrite($pipes[0], "echo <<<FOO\nFOOL\nFOO\n,1;\n");
+fwrite($pipes[0], "echo <<<FOO\nFOO4\nFOO\n,2;\n");
+fclose($pipes[0]);
+proc_close($proc);
+?>
+--EXPECTF--
+resource(%d) of type (process)
+Interactive shell
+
+php > echo <<<FOO
+<<< >     bar
+<<< >     FOO;
+bar
+php > print(<<<FOO
+<<< > xx
+<<< > FOO);
+xx
+php > echo <<<FOO
+<<< >     xxx
+<<< >     FOO;
+xxx
+php > FOO
+php > ;
+
+Warning: Use of undefined constant FOO - assumed 'FOO' (this will throw an Error in a future version of PHP) in php shell code on line %d
+php > echo <<<FOO
+<<< > FOOL
+<<< > FOO
+php > ,1;
+FOOL1
+php > echo <<<FOO
+<<< > FOO4
+<<< > FOO
+php > ,2;
+FOO42
+php >