From d7a869ffeb2f313df06d4505911cefdf8108ff7e Mon Sep 17 00:00:00 2001
From: Linnnus <linnnus@users.noreply.github.com>
Date: Sat, 17 Feb 2024 04:00:31 +0100
Subject: feat(creole): handle escaped raw URLs

---
 src/creole.c           | 26 ++++++++++++++++++++------
 src/creole_test_main.c |  5 +++++
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/creole.c b/src/creole.c
index 94e8020..c83ffd1 100644
--- a/src/creole.c
+++ b/src/creole.c
@@ -187,11 +187,21 @@ long do_link(const char *begin, const char *end, bool new_block, FILE *out)
 
 long do_raw_url(const char *begin, const char *end, bool new_block, FILE *out)
 {
+	const char *p = begin;
+
+	// This piece of spaghetti is necessary to handle escaped urls.
+	// These should not actually be turned into anchor tags.
+	// See: <http://www.wikicreole.org/wiki/Creole1.0#section-Creole1.0-EscapeCharacter>
+	bool escaped = false;
+	if (*begin == '~') {
+		escaped = true;
+		p += 1;
+	}
+
 	// Eat a scheme followed by a ":". Here are the relevant rules from RFC 3986.
 	// - URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
 	// - scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
 	// See: <https://www.rfc-editor.org/rfc/rfc3986#section-3.1>
-	const char *p = begin;
 	if (!isalpha(*p)) {
 		return 0;
 	}
@@ -240,11 +250,15 @@ end_url:
 		q -= 1;
 	}
 
-	fputs("<a href=\"", out);
-	hprint(out, begin, q);
-	fputs("\">", out);
-	hprint(out, begin, q);
-	fputs("</a>", out);
+	if (escaped) {
+		hprint(out, begin + 1 /* ~ */, q);
+	} else {
+		fputs("<a href=\"", out);
+		hprint(out, begin, q);
+		fputs("\">", out);
+		hprint(out, begin, q);
+		fputs("</a>", out);
+	}
 
 	return q - begin;
 }
diff --git a/src/creole_test_main.c b/src/creole_test_main.c
index a284811..6b9e95b 100644
--- a/src/creole_test_main.c
+++ b/src/creole_test_main.c
@@ -123,6 +123,11 @@ struct {
 		.output  =  "<p>My favorite website is <a href=\"https://wiki.c2.com/\">"
 		            "https://wiki.c2.com/</a>.</p>"
 	},
+	{
+		.name    =  "Escaped raw URL",
+		.input   =  "Please don't register ~https://cohost.org/!",
+		.output  =  "<p>Please don't register https://cohost.org/!</p>"
+	},
 	{
 		.name    =  "Unnamed URL",
 		.input   =  "[[http //example.com/examplepage]]",
-- 
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