From a3e5a9b22246665b41d04d3d7e43a204547d662c Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <moritz@bunkus.org>
Date: Sat, 15 Apr 2017 18:20:54 +0200
Subject: [PATCH] MIME: add lookup function for file name extension for MIME
 type

---
 src/common/extern_data.cpp | 7 +++++++
 src/common/extern_data.h   | 1 +
 2 files changed, 8 insertions(+)

diff --git a/src/common/extern_data.cpp b/src/common/extern_data.cpp
index bd96e5d7e..f9031f33a 100644
--- a/src/common/extern_data.cpp
+++ b/src/common/extern_data.cpp
@@ -2636,6 +2636,13 @@ guess_mime_type_by_ext(std::string ext) {
   return "";
 }
 
+std::string
+primary_file_extension_for_mime_type(std::string const &mime_type) {
+  auto itr = brng::find_if(mime_types, [&mime_type](auto const &m) { return m.name == mime_type; });
+
+  return (itr != mime_types.end()) && !itr->extensions.empty() ? itr->extensions[0] : std::string{};
+}
+
 #if HAVE_MAGIC_H
 static std::string
 guess_mime_type_by_content(magic_t &m,
diff --git a/src/common/extern_data.h b/src/common/extern_data.h
index 3fc4e7585..79327b9cf 100644
--- a/src/common/extern_data.h
+++ b/src/common/extern_data.h
@@ -37,6 +37,7 @@ extern std::vector<std::string> const g_popular_country_codes;
 extern std::vector<mime_type_t> const mime_types;
 
 std::string guess_mime_type(std::string ext, bool is_file);
+std::string primary_file_extension_for_mime_type(std::string const &mime_type);
 boost::optional<std::string> map_to_cctld(std::string const &s);
 
 #endif // MTX_COMMON_EXTERN_DATA_H