[gmime] Added some configure logic to auto-detect the system shift-jis charset alias

[Rico Tzschichholz <ricotz src gnome org>]

commit 45fe84f2d709ac968fd2f342dfd79d16a5fe2ee4
Author: Jeffrey Stedfast <jestedfa microsoft com>
Date:   Sun Feb 16 10:24:51 2020 -0500

    Added some configure logic to auto-detect the system shift-jis charset alias
    
    May fix issue #81

 gmime/gmime-charset.c | 55 ++++++++++++++++++++++++++++++++-------------------
 iconv-detect.c        | 43 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 76 insertions(+), 22 deletions(-)
---
diff --git a/gmime/gmime-charset.c b/gmime/gmime-charset.c
index 567de1bf..938de4fd 100644
--- a/gmime/gmime-charset.c
+++ b/gmime/gmime-charset.c
@@ -60,6 +60,7 @@
 #define ICONV_ISO_INT_FORMAT "iso-%u-%u"
 #define ICONV_ISO_STR_FORMAT "iso-%u-%s"
 #endif /* __aix__, __irix__, __sun__ */
+#define ICONV_SHIFT_JIS "shift-jis"
 #define ICONV_10646 "iso-10646"
 #endif /* USE_ICONV_DETECT */
 
@@ -133,12 +134,14 @@ static struct {
        /* Japanese charsets */
        { "eucjp-0",         "eucJP"      },  /* should this map to "EUC-JP" instead? */
        { "ujis-0",          "ujis"       },  /* we might want to map this to EUC-JP */
-       { "jisx0208.1983-0", "SJIS"       },
-       { "jisx0212.1990-0", "SJIS"       },
-       { "pck",             "SJIS"       },
        { NULL,              NULL         }
 };
 
+static const char *shiftjis_aliases[] = {
+       "shift-jis", "shift_jis", "sjis", "shift_jis-2004", "shift_jisx0213",
+       "jisx0208.1983-0", "jisx0212.1990-0", "pck", NULL
+};
+
 /* map CJKR charsets to their language code */
 /* NOTE: only support charset names that will be returned by
  * g_mime_charset_iconv_name() so that we don't have to keep track of
@@ -147,21 +150,20 @@ static struct {
        const char *charset;
        const char *lang;
 } cjkr_lang_map[] = {
-       { "Big5",        "zh" },
-       { "BIG5HKSCS",   "zh" },
-       { "gb2312",      "zh" },
-       { "gb18030",     "zh" },
-       { "gbk",         "zh" },
-       { "euc-tw",      "zh" },
-       { "iso-2022-jp", "ja" },
-       { "Shift-JIS",   "ja" },
-       { "sjis",        "ja" },
-       { "ujis",        "ja" },
-       { "eucJP",       "ja" },
-       { "euc-jp",      "ja" },
-       { "euc-kr",      "ko" },
-       { "koi8-r",      "ru" },
-       { "koi8-u",      "uk" }
+       { "Big5",          "zh" },
+       { "BIG5HKSCS",     "zh" },
+       { "gb2312",        "zh" },
+       { "gb18030",       "zh" },
+       { "gbk",           "zh" },
+       { "euc-tw",        "zh" },
+       { "iso-2022-jp",   "ja" },
+       { ICONV_SHIFT_JIS, "ja" },
+       { "ujis",          "ja" },
+       { "eucJP",         "ja" },
+       { "euc-jp",        "ja" },
+       { "euc-kr",        "ko" },
+       { "koi8-r",        "ru" },
+       { "koi8-u",        "uk" }
 };
 
 static GHashTable *iconv_charsets = NULL;
@@ -409,6 +411,18 @@ g_mime_charset_language (const char *charset)
        return NULL;
 }
 
+static gboolean
+is_shift_jis (const char *name)
+{
+       int i;
+       
+       for (i = 0; shiftjis_aliases[i] != NULL; i++) {
+               if (!strcmp (name, shiftjis_aliases[i]))
+                       return TRUE;
+       }
+       
+       return FALSE;
+}
 
 static const char *
 strdown (char *str)
@@ -483,8 +497,7 @@ g_mime_charset_iconv_name (const char *charset)
                                                                      iso, codepage);
                        } else {
                                /* codepage is a string - probably iso-2022-jp or something */
-                               iconv_name = g_strdup_printf (ICONV_ISO_STR_FORMAT,
-                                                             iso, p);
+                               iconv_name = g_strdup_printf (ICONV_ISO_STR_FORMAT, iso, p);
                        }
                } else {
                        /* p == buf, which probably means we've
@@ -503,6 +516,8 @@ g_mime_charset_iconv_name (const char *charset)
                        buf += 2;
                
                iconv_name = g_strdup_printf ("CP%s", buf);
+       } else if (is_shift_jis (name)) {
+               iconv_name = g_strdup (ICONV_SHIFT_JIS);
        } else {
                /* assume charset name is ok as is? */
                iconv_name = g_strdup (charset);
diff --git a/iconv-detect.c b/iconv-detect.c
index c033fd07..16333b8b 100644
--- a/iconv-detect.c
+++ b/iconv-detect.c
@@ -1,6 +1,6 @@
 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
 /*  GMime
- *  Copyright (C) 1999-2017 Jeffrey Stedfast
+ *  Copyright (C) 1999-2020 Jeffrey Stedfast
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public License
@@ -47,6 +47,12 @@ enum {
        ISO_DASH_UINT_DASH_STR_LOWER   = (1 << 0),
        ISO_DASH_UINT_DASH_STR         = (1 << 1),
        ISO_UINT_DASH_STR              = (1 << 2),
+
+       /* shift-jis */
+       SHIFT_DASH_JIS                 = (1 << 0),
+       SHIFT_UNDERSCORE_JIS           = (1 << 1),
+       SJIS                           = (1 << 2),
+       SHIFT_JISX0213                 = (1 << 3),
 };
 
 
@@ -76,6 +82,15 @@ static CharInfo iso2022_tests[] = {
 
 static int num_iso2022_tests = sizeof (iso2022_tests) / sizeof (CharInfo);
 
+static CharInfo shiftjis_tests[] = {
+       { "shift-jis",      "shift-jis",      SHIFT_DASH_JIS },
+       { "shift_jis",      "shift_jis",      SHIFT_UNDERSCORE_JIS },
+       { "sjis",           "sjis",           SJIS },
+       { "shift_jisx0213", "shift_jisx0213", SHIFT_JISX0213 },
+};
+
+static int num_shiftjis_tests = sizeof (shiftjis_tests) / sizeof (CharInfo);
+
 static CharInfo iso10646_tests[] = {
        { "iso-10646-1", "iso-%u-%u",  ISO_DASH_UINT_DASH_UINT_LOWER },
        { "ISO-10646-1", "ISO-%u-%u",  ISO_DASH_UINT_DASH_UINT },
@@ -91,7 +106,7 @@ static int num_iso10646_tests = sizeof (iso10646_tests) / sizeof (CharInfo);
 
 int main (int argc, char **argv)
 {
-       unsigned int iso8859, iso2022, iso10646;
+       unsigned int iso8859, iso2022, iso10646, shiftjis;
        CharInfo *info;
        iconv_t cd;
        FILE *fp;
@@ -150,6 +165,30 @@ int main (int argc, char **argv)
                fprintf (fp, "#define ICONV_ISO_STR_FORMAT \"%s\"\n", info[i].format);
        }
        
+       shiftjis = ISO_UNSUPPORTED;
+       info = shiftjis_tests;
+       /*printf ("#define ISO_2022_FORMAT(iso,codepage)\t");*/
+       for (i = 0; i < num_shiftjis_tests; i++) {
+               cd = iconv_open (info[i].charset, "UTF-8");
+               if (cd != (iconv_t) -1) {
+                       iconv_close (cd);
+                       /*printf ("(\"%s\", (iso), (codepage))\n", info[i].format);*/
+                       fprintf (stderr, "System prefers %s\n", info[i].charset);
+                       shiftjis = info[i].id;
+                       break;
+               }
+       }
+       
+       if (shiftjis == ISO_UNSUPPORTED) {
+               fprintf (stderr, "System doesn't support any SHIFT-JIS aliases\n");
+               fprintf (fp, "#define ICONV_SHIFT_JIS \"%s\"\n", info[0].format);
+#ifdef CONFIGURE_IN
+               return EXIT_FAILURE;
+#endif
+       } else {
+               fprintf (fp, "#define ICONV_SHIFT_JIS \"%s\"\n", info[i].format);
+       }
+       
        iso10646 = ISO_UNSUPPORTED;
        info = iso10646_tests;
        /*printf ("#define ISO_10646_FORMAT(iso,codepage)\t");*/