From e805919fe9f8becadbc0e41dd018173a9c18a99f Mon Sep 17 00:00:00 2001
From: frosch <frosch@openttd.org>
Date: Sun, 17 Oct 2010 12:12:52 +0000
Subject: (svn r20958) -Add: the concept of min-loadable-version to NewGRFs
 when choosing compatbile NewGRFs. (planetmaker)

---
 src/newgrf_config.cpp | 8 ++++++--
 src/newgrf_config.h   | 5 +++--
 2 files changed, 9 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
index 6e32fe054..b951ebfe2 100644
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -448,7 +448,7 @@ GRFListCompatibility IsGoodGRFConfigList(GRFConfig *grfconfig)
 
 			/* If we have not found the exactly matching GRF try to find one with the
 			 * same grfid, as it most likely is compatible */
-			f = FindGRFConfig(c->ident.grfid, FGCM_COMPATIBLE);
+			f = FindGRFConfig(c->ident.grfid, FGCM_COMPATIBLE, NULL, c->version);
 			if (f != NULL) {
 				md5sumToString(buf, lastof(buf), c->ident.md5sum);
 				DEBUG(grf, 1, "NewGRF %08X (%s) not found; checksum %s. Compatibility mode on", BSWAP32(c->ident.grfid), c->filename, buf);
@@ -485,6 +485,7 @@ compatible_grf:
 				if (c->info == NULL) c->info = DuplicateGRFText(f->info);
 				c->error = NULL;
 				c->version = f->version;
+				c->min_loadable_version = f->min_loadable_version;
 				c->num_valid_params = f->num_valid_params;
 				c->has_param_defaults = f->has_param_defaults;
 				for (uint i = 0; i < f->param_info.Length(); i++) {
@@ -616,9 +617,10 @@ void ScanNewGRFFiles()
  * @param grfid GRFID to look for,
  * @param mode Restrictions for matching grfs
  * @param md5sum Expected MD5 sum
+ * @param desired_version Requested version
  * @return The matching grf, if it exists in #_all_grfs, else \c NULL.
  */
-const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8 *md5sum)
+const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8 *md5sum, uint32 desired_version)
 {
 	assert((mode == FGCM_EXACT) != (md5sum == NULL));
 	const GRFConfig *best = NULL;
@@ -627,6 +629,8 @@ const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8
 		if (!c->ident.HasGrfIdentifier(grfid, md5sum)) continue;
 		/* return it, if the exact same newgrf is found, or if we do not care about finding "the best" */
 		if (md5sum != NULL || mode == FGCM_ANY) return c;
+		/* check version compatibility */
+		if (mode == FGCM_COMPATIBLE && (c->version < desired_version || c->min_loadable_version > desired_version)) continue;
 		/* remember the newest one as "the best" */
 		if (best == NULL || c->version > best->version) best = c;
 	}
diff --git a/src/newgrf_config.h b/src/newgrf_config.h
index 085791282..7dfa06ac6 100644
--- a/src/newgrf_config.h
+++ b/src/newgrf_config.h
@@ -143,6 +143,7 @@ struct GRFConfig : ZeroedMemoryAllocator {
 	GRFError *error;           ///< NOSAVE: Error/Warning during GRF loading (Action 0x0B)
 
 	uint32 version;            ///< NOSAVE: Version a NewGRF can set so only the newest NewGRF is shown
+	uint32 min_loadable_version;                   ///< NOSAVE: Minimum compatible version a NewGRF can define
 	uint8 flags;               ///< NOSAVE: GCF_Flags, bitset
 	GRFStatus status;          ///< NOSAVE: GRFStatus, enum
 	uint32 grf_bugs;           ///< NOSAVE: bugs in this GRF in this run, @see enum GRFBugs
@@ -167,7 +168,7 @@ struct GRFConfig : ZeroedMemoryAllocator {
 /** Method to find GRFs using FindGRFConfig */
 enum FindGRFConfigMode {
 	FGCM_EXACT,       ///< Only find Grfs matching md5sum
-	FGCM_COMPATIBLE,  ///< Find best compatible
+	FGCM_COMPATIBLE,  ///< Find best compatible Grf wrt. desired_version
 	FGCM_NEWEST,      ///< Find newest Grf
 	FGCM_ANY,         ///< Use first found
 };
@@ -179,7 +180,7 @@ extern GRFConfig *_grfconfig_static;  ///< First item in list of static GRF set
 
 void ScanNewGRFFiles();
 void CheckForMissingSprites();
-const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8 *md5sum = NULL);
+const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8 *md5sum = NULL, uint32 desired_version = 0);
 GRFConfig *GetGRFConfig(uint32 grfid, uint32 mask = 0xFFFFFFFF);
 GRFConfig **CopyGRFConfigList(GRFConfig **dst, const GRFConfig *src, bool init_only);
 void AppendStaticGRFConfigs(GRFConfig **dst);
-- 
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