html: Avoid infinite ping-pong loop with JSP tags

Fix #4097

JSP tags shouldn't trigger the PHP parser.  This used to happen and
trigger an infinite loop of a ping-pong effect with the HTML parser
asking the PHP parser to parse the JSP block, and the PHP parser, not
recognizing the input, asking the HTML one to deal with it.  Rinse and
repeat.

Author: b4n

Units/parser-html.r/jsp.d/README

@@ -0,0 +1,6 @@
+JSP tags shouldn't trigger the PHP parser.
+
+This used to happen and trigger an infinite loop of a ping-pong effect
+with the HTML parser asking the PHP parser to parse the JSP block, and
+the PHP parser, not recognizing the input, asking the HTML one to deal
+with it.  Rinse and repeat.

Units/parser-html.r/jsp.d/args.ctags

@@ -0,0 +1,2 @@
+--sort=no
+--extras='*'

Units/parser-html.r/jsp.d/input.html

@@ -0,0 +1 @@
+<%=

parsers/html.c

@@ -356,7 +356,7 @@ static void readToken (tokenInfo *const token, bool skipComments, bool asJSX)
 				ungetcToInputFile (d);
 				token->type = TOKEN_OTHER;
 			}
-			else if (d == '?' || d == '%')
+			else if (d == '?')
 			{
 				skipOtherScriptContent(d);
 				goto getNextChar;