Store the crawl version in the textdatabases in SAVEDIR and
upgrade the databases when the crawl version changes.

By default crawl checks for a mtime difference on files in DATADIR to see if an
upgrade is required, but guix nulls all file dates,
and crawl would never upgrade saves.

diff -ur a/source/database.cc b/source/database.cc
--- a/crawl-ref/source/database.cc	2018-08-09 21:49:26.000000000 -0400
+++ b/crawl-ref/source/database.cc	2018-10-07 18:06:41.022445789 -0400
@@ -24,6 +24,7 @@
 #include "stringutil.h"
 #include "syscalls.h"
 #include "unicode.h"
+#include "version.h"
 
 // TextDB handles dependency checking the db vs text files, creating the
 // db, loading, and destroying the DB.
@@ -54,6 +55,7 @@
     vector<string> _input_files;
     DBM* _db;
     string timestamp;
+    string version;
     TextDB *_parent;
     const char* lang() { return _parent ? Options.lang_name : 0; }
 public:
@@ -163,7 +165,7 @@
 
 TextDB::TextDB(const char* db_name, const char* dir, vector<string> files)
     : _db_name(db_name), _directory(dir), _input_files(files),
-      _db(nullptr), timestamp(""), _parent(0), translation(0)
+      _db(nullptr), timestamp(""), version(""),  _parent(0), translation(0)
 {
 }
 
@@ -171,7 +173,7 @@
     : _db_name(parent->_db_name),
       _directory(parent->_directory + Options.lang_name + "/"),
       _input_files(parent->_input_files), // FIXME: pointless copy
-      _db(nullptr), timestamp(""), _parent(parent), translation(nullptr)
+      _db(nullptr), timestamp(""), version(""), _parent(parent), translation(nullptr)
 {
 }
 
@@ -186,6 +188,9 @@
         return false;
 
     timestamp = _query_database(*this, "TIMESTAMP", false, false, true);
+    version = _query_database(*this, "VERSION", false, false, true);
+    if (version.empty())
+        return false;
     if (timestamp.empty())
         return false;
 
@@ -229,6 +234,9 @@
     string ts;
     bool no_files = true;
 
+    if (string(Version::Long) != version)
+        return true;
+
     for (const string &file : _input_files)
     {
         string full_input_path = _directory + file;
@@ -246,7 +254,7 @@
         ts += buf;
     }
 
-    if (no_files)
+    if (no_files && version.empty())
     {
         // No point in empty databases, although for simplicity keep ones
         // for disappeared translations for now.
@@ -312,7 +320,10 @@
             _store_text_db(full_input_path, _db);
         }
     }
+
+    string current_version = string(Version::Long);
     _add_entry(_db, "TIMESTAMP", ts);
+    _add_entry(_db, "VERSION", current_version);
 
     dbm_close(_db);
     _db = 0;
title='2023-02-19 21:13:23 -0500'>2023-02-19</span></td><td><a href='/guix/commit/etc/snippets/yas?id=633ead4afc78cfe65d9c8e629a4af4a80d969eb4'>etc: Add a news entry snippet.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/scheme-mode/guix-news-entry: New file.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-11-28 23:34:15 +0100'>2022-11-28</span></td><td><a href='/guix/commit/etc/snippets/yas?id=fcb59fe24afc064b87b3abaf91140d015b4eb889'>snippets: yas: Add snippets for vc.el</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-add-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-remove-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-rename-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-update-package:
* etc/snippets/yas/log-edit-mode/guix-vc-commit-message-use-https-home-page:
New file

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Morgan Smith</td></tr>
<tr><td><span title='2022-08-30 11:50:15 +0200'>2022-08-30</span></td><td><a href='/guix/commit/etc/snippets/yas?id=47c11772dfe840a536ed7ec438fe832878f51054'>etc: Update yasnippet build system list.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/yas/scheme-mode/guix-package (build-system): Add
chicken-build-system, minetest-build-system, rebar-build-system
and renpy-build-system.

Signed-off-by: Liliana Marie Prikler &lt;liliana.prikler@gmail.com&gt;
</span></span></td><td>Nicolas Graves</td></tr>
<tr><td><span title='2022-08-30 11:50:14 +0200'>2022-08-30</span></td><td><a href='/guix/commit/etc/snippets/yas?id=c4acaf412064568a546034871a9e0d3888aa7937'>etc: Add tempel snippets.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/snippets/tempel/scheme-mode: New file.
* etc/snippets/tempel/text-mode: New file.
* etc/snippets/scheme-mode: Moved from here...
* etc/snippets/yas/scheme-mode: ... to here.
* etc/snippets/text-mode: Moved from here...
* etc/snippets/yas/text-mode: ... to here.
* doc/contributing.texi ("The Perfect Setup"): Adjust yasnippet setup
accordingly.  Add tempel setup.

Signed-off-by: Liliana Marie Prikler &lt;liliana.prikler@gmail.com&gt;
</span></span></td><td>Nicolas Graves</td></tr>