CFamilyLexer: refuse quotes between parentheses for function definitions and declarations (#2208)

Something like

id id2("){ ... }");

is no longer wrongly recognized as a "function"

id id2(") {
  ...
}
");

As the difference in the tests shows, this has the unfortunate side
effect that we no longer highlight something like

int f(param="default");

as a function declaration, but it is hard to imagine another way to
fix this (cf. “most vexing parse” problem).

Fixes #2207

1 files changed, 41 insertions, 0 deletions

diff --git a/tests/snippets/c/test_string_resembling_decl_end.txt b/tests/snippets/c/test_string_resembling_decl_end.txt
new file mode 100644
index 00000000..17ce2233
--- /dev/null
+++ b/tests/snippets/c/test_string_resembling_decl_end.txt
@@ -0,0 +1,41 @@
+---input---
+// This should not be recognized as a function declaration followed by
+// garbage.
+string xyz(");");
+
+// This should not be recognized as a function definition.
+
+string xyz("){ }");
+
+---tokens---
+'// This should not be recognized as a function declaration followed by\n' Comment.Single
+
+'// garbage.\n' Comment.Single
+
+'string'      Name
+' '           Text.Whitespace
+'xyz'         Name
+'('           Punctuation
+'"'           Literal.String
+');'          Literal.String
+'"'           Literal.String
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace
+
+'\n'          Text.Whitespace
+
+'// This should not be recognized as a function definition.\n' Comment.Single
+
+'\n'          Text.Whitespace
+
+'string'      Name
+' '           Text.Whitespace
+'xyz'         Name
+'('           Punctuation
+'"'           Literal.String
+'){ }'        Literal.String
+'"'           Literal.String
+')'           Punctuation
+';'           Punctuation
+'\n'          Text.Whitespace