fix #29781, disallow spaces in broadcast calls (#30182)

NEWS.md

@@ -11,6 +11,8 @@ Language changes
 
  * Parser inputs ending with a comma are now consistently treated as incomplete.
  Previously they were sometimes parsed as tuples, depending on whitespace ([#28506]).
+ * Spaces were accidentally allowed in broadcast call syntax, e.g. `f. (x)`. They are now
+ disallowed, consistent with normal function call syntax ([#29781]).
  * Big integer literals and command syntax (backticks) are now parsed with the name of
  the macro (`@int128_str`, `@uint128_str`, `@big_str`, `@cmd`) qualified to refer
  to the `Core` module ([#29968]).

src/julia-parser.scm

@@ -1201,6 +1201,9 @@
  (loop
  (cond ((eqv? (peek-token s) #\()
  (begin
+ (if (ts:space? s)
+ (error (string "space before \"(\" not allowed in \""
+ (deparse ex) ". (\"")))
  (take-token s)
  `(|.| ,ex (tuple ,@(parse-call-arglist s #\) )))))
  ((eqv? (peek-token s) ':)

test/syntax.jl

@@ -1328,6 +1328,8 @@ end
 @test Meta.parse("+((1,2))") == Expr(:call, :+, Expr(:tuple, 1, 2))
 
 @test_throws ParseError("space before \"(\" not allowed in \"+ (\"") Meta.parse("1 -+ (a=1, b=2)")
+# issue #29781
+@test_throws ParseError("space before \"(\" not allowed in \"sin. (\"") Meta.parse("sin. (1)")
 
 @test Meta.parse("1 -+(a=1, b=2)") == Expr(:call, :-, 1,
  Expr(:call, :+, Expr(:kw, :a, 1), Expr(:kw, :b, 2)))