t4018-diff-funcname: test syntax of builtin xfuncname patterns

[jc: fixes bibtex pattern breakage exposed by this test]
Signed-off-by: NBrandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

diff.c

@@ -1404,7 +1404,7 @@ static const struct funcname_pattern_entry *funcname_pattern(const char *ident)
 }
 
 static const struct funcname_pattern_entry builtin_funcname_pattern[] = {
-	{ "bibtex", "(@[a-zA-Z]{1,}[ \t]*\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
+	{ "bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
 	  REG_EXTENDED },
 	{ "html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$", REG_EXTENDED },
 	{ "java",

t/t4018-diff-funcname.sh

@@ -32,7 +32,7 @@ EOF
 
 sed 's/beer\\/beer,\\/' < Beer.java > Beer-correct.java
 
-builtin_patterns="bibtex java pascal ruby tex"
+builtin_patterns="bibtex html java pascal php python ruby tex"
 for p in $builtin_patterns
 do
 	test_expect_success "builtin $p pattern compiles" '