[evolution-data-server/gnome-3-28] Bug 796116 - [webcal] Skip UTF-8 marker when parsing iCalendar string

[Milan Crha <mcrha src gnome org>]

commit 8d53a17adb27a7087e763c6f1226489c89c219b5
Author: Milan Crha <mcrha redhat com>
Date:   Mon May 21 18:37:00 2018 +0200

    Bug 796116 - [webcal] Skip UTF-8 marker when parsing iCalendar string

 src/calendar/backends/http/e-cal-backend-http.c |    8 +++-
 src/calendar/libecal/e-cal-util.c               |   54 +++++++++++++++++++---
 2 files changed, 53 insertions(+), 9 deletions(-)
---
diff --git a/src/calendar/backends/http/e-cal-backend-http.c b/src/calendar/backends/http/e-cal-backend-http.c
index 4f86c5c..cbeb2d8 100644
--- a/src/calendar/backends/http/e-cal-backend-http.c
+++ b/src/calendar/backends/http/e-cal-backend-http.c
@@ -341,7 +341,13 @@ ecb_http_get_changes_sync (ECalMetaBackend *meta_backend,
                return FALSE;
        }
 
-       maincomp = icalparser_parse_string (icalstring);
+       /* Skip the UTF-8 marker at the beginning of the string */
+       if (((guchar) icalstring[0]) == 0xEF &&
+           ((guchar) icalstring[1]) == 0xBB &&
+           ((guchar) icalstring[2]) == 0xBF)
+               maincomp = icalparser_parse_string (icalstring + 3);
+       else
+               maincomp = icalparser_parse_string (icalstring);
 
        g_free (icalstring);
 
diff --git a/src/calendar/libecal/e-cal-util.c b/src/calendar/libecal/e-cal-util.c
index b257c49..09749dd 100644
--- a/src/calendar/libecal/e-cal-util.c
+++ b/src/calendar/libecal/e-cal-util.c
@@ -207,12 +207,48 @@ e_cal_util_parse_ics_string (const gchar *string)
        return icalcomp;
 }
 
+struct ics_file {
+       FILE *file;
+       gboolean bof;
+};
+
 static gchar *
 get_line_fn (gchar *buf,
-             gsize size,
-             gpointer file)
+            gsize size,
+            gpointer user_data)
 {
-       return fgets (buf, size, file);
+       struct ics_file *fl = user_data;
+
+       /* Skip the UTF-8 marker at the beginning of the file */
+       if (fl->bof) {
+               gchar *orig_buf = buf;
+               gchar tmp[4];
+
+               fl->bof = FALSE;
+
+               if (fread (tmp, sizeof (gchar), 3, fl->file) != 3 || feof (fl->file))
+                       return NULL;
+
+               if (((guchar) tmp[0]) != 0xEF ||
+                   ((guchar) tmp[1]) != 0xBB ||
+                   ((guchar) tmp[2]) != 0xBF) {
+                       if (size <= 3)
+                               return NULL;
+
+                       buf[0] = tmp[0];
+                       buf[1] = tmp[1];
+                       buf[2] = tmp[2];
+                       buf += 3;
+                       size -= 3;
+               }
+
+               if (!fgets (buf, size, fl->file))
+                       return NULL;
+
+               return orig_buf;
+       }
+
+       return fgets (buf, size, fl->file);
 }
 
 /**
@@ -230,18 +266,20 @@ e_cal_util_parse_ics_file (const gchar *filename)
 {
        icalparser *parser;
        icalcomponent *icalcomp;
-       FILE *file;
+       struct ics_file fl;
 
-       file = g_fopen (filename, "rb");
-       if (!file)
+       fl.file = g_fopen (filename, "rb");
+       if (!fl.file)
                return NULL;
 
+       fl.bof = TRUE;
+
        parser = icalparser_new ();
-       icalparser_set_gen_data (parser, file);
+       icalparser_set_gen_data (parser, &fl);
 
        icalcomp = icalparser_parse (parser, get_line_fn);
        icalparser_free (parser);
-       fclose (file);
+       fclose (fl.file);
 
        return icalcomp;
 }