termux-packages/packages/glib/glib-gtimezone.c.patch

Patch submitted at https://bugzilla.gnome.org/show_bug.cgi?id=771304

diff -u -r ../glib-2.48.2/glib/gtimezone.c ./glib/gtimezone.c
--- ../glib-2.48.2/glib/gtimezone.c	2016-08-17 12:07:29.000000000 -0400
+++ ./glib/gtimezone.c	2016-09-12 16:52:41.864974630 -0400
@@ -43,6 +43,11 @@
 #include <windows.h>
 #endif
 
+#ifdef __ANDROID__
+#include <fcntl.h>
+#include <sys/system_properties.h>
+#endif
+
 /**
  * SECTION:timezone
  * @title: GTimeZone
@@ -396,6 +400,75 @@
 static GBytes*
 zone_info_unix (const gchar *identifier)
 {
+#ifdef __ANDROID__
+  /* Android does not have /etc/localtime but uses a system property for the
+     the current timezone. There are no files under /usr/share/zoneinfo,
+     instead a single /system/usr/share/zoneinfo/tzdata which are all zoneinfo
+     files compiled together with the following tool:
+     https://android.googlesource.com/platform/external/icu/+/master/tools/ZoneCompactor.java */
+  struct tzdata_header {
+    char version[12];
+    uint32_t index_offset, data_offset, zonetab_offset;
+  } __attribute__((packed)) header;
+
+  struct tzdata_index_entry {
+    char name[40];
+    uint32_t offset, length, unused;
+  } __attribute__((packed)) entry;
+
+  char sys_timezone[PROP_VALUE_MAX];
+  if (identifier == NULL) {
+    if (__system_property_get("persist.sys.timezone", sys_timezone) < 1) {
+      g_warning("__system_property_get(\"persist.sys.timezone\") failed\n");
+      return NULL;
+    }
+    identifier = sys_timezone;
+  }
+  if (identifier != NULL) {
+    int tzdata_fd = open("/system/usr/share/zoneinfo/tzdata", O_RDONLY);
+    if (tzdata_fd < 0) {
+      g_warning("Failed opening tzdata");
+      return NULL;
+    }
+    if (read(tzdata_fd, &header, sizeof(header)) < (ssize_t) sizeof(header)) {
+      g_warning("Failed reading tzdata header");
+      goto error;
+    }
+    header.index_offset = htonl(header.index_offset);
+    header.data_offset = htonl(header.data_offset);
+
+    uint32_t current_offset = header.index_offset;
+    while (current_offset < header.data_offset) {
+      if (read(tzdata_fd, &entry, sizeof(entry)) < (ssize_t) sizeof(entry)) {
+        g_warning("Failed reading tzdata index entry");
+        goto error;
+      }
+      if (strcmp(entry.name, identifier) == 0) {
+        entry.offset = htonl(entry.offset);
+        entry.length = htonl(entry.length);
+        if (entry.length == 0) {
+          g_warning("Invalid tzdata entry with length zero");
+          goto error;
+        }
+        if (lseek(tzdata_fd, header.data_offset + entry.offset, SEEK_SET) == -1) {
+          g_warning("Failed seeking to tzdata entry");
+          goto error;
+        }
+        guint8* data = g_malloc(entry.length);
+        if (read(tzdata_fd, data, entry.length) < entry.length) {
+          g_warning("Failed reading tzdata entry");
+          g_free(data);
+          goto error;
+        }
+        close(tzdata_fd);
+        return g_bytes_new_take(data, entry.length);
+      }
+    }
+error:
+    close(tzdata_fd);
+  }
+  return NULL;
+#else
   gchar *filename;
   GMappedFile *file = NULL;
   GBytes *zoneinfo = NULL;
@@ -434,6 +497,7 @@
     }
   g_free (filename);
   return zoneinfo;
+#endif
 }
 
 static void