Print announce error response (#11878)

Fix HTTPFetch caller and request ID to 64 bits
Check that allocated caller ID is not DISCARD
Print body if serverlist request returns error
Don't print control characters from HTTP responses
Document special HTTPFetch caller IDs
Allow unicode to be printed

2 files changed, 24 insertions, 0 deletions

diff --git a/src/util/string.cpp b/src/util/string.cpp
index 8be5e320a..bc4664997 100644
--- a/src/util/string.cpp
+++ b/src/util/string.cpp
@@ -887,3 +887,19 @@ std::string sanitizeDirName(const std::string &str, const std::string &optional_
 
 	return wide_to_utf8(safe_name);
 }
+
+
+void safe_print_string(std::ostream &os, const std::string &str)
+{
+	std::ostream::fmtflags flags = os.flags();
+	os << std::hex;
+	for (const char c : str) {
+		if (IS_ASCII_PRINTABLE_CHAR(c) || IS_UTF8_MULTB_START(c) ||
+				IS_UTF8_MULTB_INNER(c) || c == '\n' || c == '\t') {
+			os << c;
+		} else {
+			os << '<' << std::setw(2) << (int)c << '>';
+		}
+	}
+	os.setf(flags);
+}
diff --git a/src/util/string.h b/src/util/string.h
index bca998f56..8a9e83f22 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -753,3 +753,11 @@ inline irr::core::stringw utf8_to_stringw(const std::string &input)
  * 2. Remove 'unsafe' characters from the name by replacing them with '_'
  */
 std::string sanitizeDirName(const std::string &str, const std::string &optional_prefix);
+
+/**
+ * Prints a sanitized version of a string without control characters.
+ * '\t' and '\n' are allowed, as are UTF-8 control characters (e.g. RTL).
+ * ASCII control characters are replaced with their hex encoding in angle
+ * brackets (e.g. "a\x1eb" -> "a<1e>b").
+ */
+void safe_print_string(std::ostream &os, const std::string &str);