gnu: crawl: Fix savegame upgrades.

* gnu/packages/patches/crawl-upgrade-saves.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add patch.
* gnu/packages/games.scm (crawl)[source]: Apply patch.

Signed-off-by: Arun Isaac <arunisaac@systemreboot.net>

gnu/local.mk

@@ -550,6 +550,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/cpufrequtils-fix-aclocal.patch		\
   %D%/packages/patches/cracklib-CVE-2016-6318.patch		\
   %D%/packages/patches/cracklib-fix-buffer-overflow.patch	\
+  %D%/packages/patches/crawl-upgrade-saves.patch		\
   %D%/packages/patches/crda-optional-gcrypt.patch		\
   %D%/packages/patches/crossmap-allow-system-pysam.patch	\
   %D%/packages/patches/csound-header-ordering.patch		\

gnu/packages/games.scm

@@ -4049,7 +4049,8 @@ (define-public crawl
                             version "-nodeps.tar.xz")))
        (sha256
         (base32
-         "0127dgldij2h4m7cf32yy9ndv4vcz03g4km71lmxrsi5mw7ljgpd"))))
+         "0127dgldij2h4m7cf32yy9ndv4vcz03g4km71lmxrsi5mw7ljgpd"))
+       (patches (search-patches "crawl-upgrade-saves.patch"))))
     (build-system gnu-build-system)
     (inputs
      `(("lua51" ,lua-5.1)
@@ -4101,6 +4102,9 @@ (define-public crawl
                    license:zlib
                    license:asl2.0))))
 
+;; The linter here claims that patch file names should start with the package
+;; name. But, in this case, the patches are inherited from crawl with the
+;; "crawl-" prefix instead of "crawl-tiles-".
 (define-public crawl-tiles
   (package
     (inherit crawl)

gnu/packages/patches/crawl-upgrade-saves.patch

@@ -0,0 +1,83 @@
+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.
+
+--- a/source/database.cc	2016-05-31 09:56:08.000000000 +0200
++++ a/source/database.cc	2017-06-05 03:00:19.270632107 +0200
+@@ -25,6 +25,7 @@
+ #include "syscalls.h"
+ #include "threads.h"
+ #include "unicode.h"
++#include "version.h"
+ 
+ // TextDB handles dependency checking the db vs text files, creating the
+ // db, loading, and destroying the DB.
+@@ -55,6 +56,7 @@
+     vector<string> _input_files;
+     DBM* _db;
+     string timestamp;
++    string version;
+     TextDB *_parent;
+     const char* lang() { return _parent ? Options.lang_name : 0; }
+ public:
+@@ -165,7 +167,7 @@
+ 
+ TextDB::TextDB(const char* db_name, const char* dir, ...)
+     : _db_name(db_name), _directory(dir),
+-      _db(nullptr), timestamp(""), _parent(0), translation(0)
++      _db(nullptr), timestamp(""), version(""),  _parent(0), translation(0)
+ {
+     va_list args;
+     va_start(args, dir);
+@@ -187,7 +189,7 @@
+     : _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)
+ {
+ }
+ 
+@@ -202,6 +204,9 @@
+         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;
+ 
+@@ -245,6 +250,9 @@
+     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;
+@@ -261,7 +269,7 @@
+         ts += buf;
+     }
+ 
+-    if (no_files && timestamp.empty())
++    if (no_files && timestamp.empty() && version.empty())
+     {
+         // No point in empty databases, although for simplicity keep ones
+         // for disappeared translations for now.
+@@ -321,7 +329,10 @@
+             _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;