[vte] lib: Add missing files

[Christian Persch <chpe src gnome org>]

commit 55e5d53676960feb5dc11400ecdc7c9d7c4ab13e
Author: Christian Persch <chpe src gnome org>
Date:   Sun Nov 17 22:15:38 2019 +0100

    lib: Add missing files

 src/icu-glue.cc | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/icu-glue.hh |  34 ++++++++++++++++
 2 files changed, 155 insertions(+)
---
diff --git a/src/icu-glue.cc b/src/icu-glue.cc
new file mode 100644
index 00000000..d86f23c3
--- /dev/null
+++ b/src/icu-glue.cc
@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2019 Christian Persch
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include <cstring>
+
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <unicode/errorcode.h>
+#include <unicode/ucnv.h>
+
+#include "icu-glue.hh"
+
+namespace vte::base {
+
+/* VTE cannot use the converters for ECMA-35 (ISO-2022-*), since they
+ * interpret escape sequences (for charset designation), and do not
+ * (and *cannot*, without having a complete escape sequence parser)
+ * let through the non-designation sequences.
+ *
+ * The user will need to use luit(1) instead.
+ */
+
+bool
+get_icu_charset_is_ecma35(char const* charset)
+{
+        return strstr(charset, "2022") != nullptr;
+}
+
+char**
+get_icu_charsets(bool aliases)
+{
+        auto count = ucnv_countAvailable();
+        auto names = std::vector<std::string>{};
+        names.reserve(count);
+
+        for (auto i = 0; i < count; ++i) {
+                auto name = ucnv_getAvailableName(i);
+                if (get_icu_charset_is_ecma35(name))
+                        continue;
+
+                if (!aliases) {
+                        names.push_back(name);
+                        continue;
+                }
+
+                auto err = icu::ErrorCode{};
+                auto acount = ucnv_countAliases(name, err);
+                if (err.isFailure()) {
+                        names.push_back(name);
+                        continue;
+                }
+
+                /* The aliases will include @name */
+
+                for (auto j = 0; j < acount; ++j) {
+                        err.reset();
+                        auto alias = ucnv_getAlias(name, j, err);
+                        if (err.isFailure())
+                                continue;
+                        names.push_back(alias);
+                }
+        }
+
+        /* Sort the charsets list */
+        std::sort(names.begin(), names.end());
+
+        auto r = g_new0(char*, names.size() + 1);
+        auto n = r;
+        for (auto const& name : names)
+                *n++ = g_strdup(name.c_str());
+        *n++ = nullptr;
+
+        return r;
+}
+
+bool
+get_icu_charset_supported(char const* charset)
+{
+        if (get_icu_charset_is_ecma35(charset))
+                return false;
+
+        auto err = icu::ErrorCode{};
+        auto count = ucnv_countAliases(charset, err);
+        return err.isSuccess() && count != 0;
+}
+
+std::shared_ptr<UConverter>
+make_icu_converter(char const* charset,
+                   GError** error)
+{
+        auto err = icu::ErrorCode{};
+        auto converter = std::shared_ptr<UConverter>{ucnv_open(charset, err), &ucnv_close};
+        if (err.isFailure())
+                g_set_error(error, G_CONVERT_ERROR, G_CONVERT_ERROR_NO_CONVERSION,
+                            "Failed to open converter for charset \"%s\": %s",
+                            charset, err.errorName());
+        return converter;
+}
+
+} // namespace vte::base
diff --git a/src/icu-glue.hh b/src/icu-glue.hh
new file mode 100644
index 00000000..3c61ae99
--- /dev/null
+++ b/src/icu-glue.hh
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2019 Christian Persch
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <glib.h>
+#include <memory>
+
+namespace vte::base {
+
+char** get_icu_charsets(bool aliases = true);
+
+bool get_icu_charset_supported(char const* charset);
+
+bool get_icu_charset_is_ecma35(char const* charset);
+
+std::shared_ptr<UConverter> make_icu_converter(char const* charset,
+                                               GError** error = nullptr);
+
+} // namespace vte::base