summaryrefslogtreecommitdiff
path: root/src/newgrf_config.cpp
blob: 911d266df05294b5ffe48c06a9476c824f983825 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file newgrf_config.cpp Finding NewGRFs and configuring them. */

#include "stdafx.h"
#include "debug.h"
#include "3rdparty/md5/md5.h"
#include "newgrf.h"
#include "network/network_func.h"
#include "gfx_func.h"
#include "newgrf_text.h"
#include "window_func.h"
#include "progress.h"
#include "video/video_driver.hpp"
#include "strings_func.h"
#include "textfile_gui.h"
#include "thread.h"
#include "newgrf_config.h"
#include "newgrf_text.h"

#include "fileio_func.h"
#include "fios.h"

#include "safeguards.h"


/**
 * Create a new GRFConfig.
 * @param filename Set the filename of this GRFConfig to filename. The argument
 *   is copied so the original string isn't needed after the constructor.
 */
GRFConfig::GRFConfig(const char *filename) :
	num_valid_params(lengthof(param))
{
	if (filename != nullptr) this->filename = stredup(filename);
}

/**
 * Create a new GRFConfig that is a deep copy of an existing config.
 * @param config The GRFConfig object to make a copy of.
 */
GRFConfig::GRFConfig(const GRFConfig &config) :
	ZeroedMemoryAllocator(),
	ident(config.ident),
	name(config.name),
	info(config.info),
	url(config.url),
	version(config.version),
	min_loadable_version(config.min_loadable_version),
	flags(config.flags & ~(1 << GCF_COPY)),
	status(config.status),
	grf_bugs(config.grf_bugs),
	num_params(config.num_params),
	num_valid_params(config.num_valid_params),
	palette(config.palette),
	has_param_defaults(config.has_param_defaults)
{
	MemCpyT<uint8>(this->original_md5sum, config.original_md5sum, lengthof(this->original_md5sum));
	MemCpyT<uint32>(this->param, config.param, lengthof(this->param));
	if (config.filename != nullptr) this->filename = stredup(config.filename);
	if (config.error != nullptr) this->error = new GRFError(*config.error);
	for (uint i = 0; i < config.param_info.size(); i++) {
		if (config.param_info[i] == nullptr) {
			this->param_info.push_back(nullptr);
		} else {
			this->param_info.push_back(new GRFParameterInfo(*config.param_info[i]));
		}
	}
}

/** Cleanup a GRFConfig object. */
GRFConfig::~GRFConfig()
{
	/* GCF_COPY as in NOT stredupped/alloced the filename */
	if (!HasBit(this->flags, GCF_COPY)) {
		free(this->filename);
		delete this->error;
	}

	for (uint i = 0; i < this->param_info.size(); i++) delete this->param_info[i];
}

/**
 * Copy the parameter information from the \a src config.
 * @param src Source config.
 */
void GRFConfig::CopyParams(const GRFConfig &src)
{
	this->num_params = src.num_params;
	this->num_valid_params = src.num_valid_params;
	MemCpyT<uint32>(this->param, src.param, lengthof(this->param));
}

/**
 * Get the name of this grf. In case the name isn't known
 * the filename is returned.
 * @return The name of filename of this grf.
 */
const char *GRFConfig::GetName() const
{
	const char *name = GetGRFStringFromGRFText(this->name);
	return StrEmpty(name) ? this->filename : name;
}

/**
 * Get the grf info.
 * @return A string with a description of this grf.
 */
const char *GRFConfig::GetDescription() const
{
	return GetGRFStringFromGRFText(this->info);
}

/**
 * Get the grf url.
 * @return A string with an url of this grf.
 */
const char *GRFConfig::GetURL() const
{
	return GetGRFStringFromGRFText(this->url);
}

/** Set the default value for all parameters as specified by action14. */
void GRFConfig::SetParameterDefaults()
{
	this->num_params = 0;
	MemSetT<uint32>(this->param, 0, lengthof(this->param));

	if (!this->has_param_defaults) return;

	for (uint i = 0; i < this->param_info.size(); i++) {
		if (this->param_info[i] == nullptr) continue;
		this->param_info[i]->SetValue(this, this->param_info[i]->def_value);
	}
}

/**
 * Set the palette of this GRFConfig to something suitable.
 * That is either the setting coming from the NewGRF or
 * the globally used palette.
 */
void GRFConfig::SetSuitablePalette()
{
	PaletteType pal;
	switch (this->palette & GRFP_GRF_MASK) {
		case GRFP_GRF_DOS:     pal = PAL_DOS;      break;
		case GRFP_GRF_WINDOWS: pal = PAL_WINDOWS;  break;
		default:               pal = _settings_client.gui.newgrf_default_palette == 1 ? PAL_WINDOWS : PAL_DOS; break;
	}
	SB(this->palette, GRFP_USE_BIT, 1, pal == PAL_WINDOWS ? GRFP_USE_WINDOWS : GRFP_USE_DOS);
}

/**
 * Finalize Action 14 info after file scan is finished.
 */
void GRFConfig::FinalizeParameterInfo()
{
	for (GRFParameterInfo *info : this->param_info) {
		if (info == nullptr) continue;
		info->Finalize();
	}
}

GRFConfig *_all_grfs;
GRFConfig *_grfconfig;
GRFConfig *_grfconfig_newgame;
GRFConfig *_grfconfig_static;
uint _missing_extra_graphics = 0;

/**
 * Construct a new GRFError.
 * @param severity The severity of this error.
 * @param message The actual error-string.
 */
GRFError::GRFError(StringID severity, StringID message) :
	message(message),
	severity(severity),
	param_value()
{
}

/**
 * Create a new GRFError that is a deep copy of an existing error message.
 * @param error The GRFError object to make a copy of.
 */
GRFError::GRFError(const GRFError &error) :
	custom_message(error.custom_message),
	data(error.data),
	message(error.message),
	severity(error.severity)
{
	memcpy(this->param_value, error.param_value, sizeof(this->param_value));
}

/**
 * Create a new empty GRFParameterInfo object.
 * @param nr The newgrf parameter that is changed.
 */
GRFParameterInfo::GRFParameterInfo(uint nr) :
	name(),
	desc(),
	type(PTYPE_UINT_ENUM),
	min_value(0),
	max_value(UINT32_MAX),
	def_value(0),
	param_nr(nr),
	first_bit(0),
	num_bit(32),
	value_names(),
	complete_labels(false)
{}

/**
 * Create a new GRFParameterInfo object that is a deep copy of an existing
 *   parameter info object.
 * @param info The GRFParameterInfo object to make a copy of.
 */
GRFParameterInfo::GRFParameterInfo(GRFParameterInfo &info) :
	name(info.name),
	desc(info.desc),
	type(info.type),
	min_value(info.min_value),
	max_value(info.max_value),
	def_value(info.def_value),
	param_nr(info.param_nr),
	first_bit(info.first_bit),
	num_bit(info.num_bit),
	value_names(info.value_names),
	complete_labels(info.complete_labels)
{
}

/**
 * Get the value of this user-changeable parameter from the given config.
 * @param config The GRFConfig to get the value from.
 * @return The value of this parameter.
 */
uint32 GRFParameterInfo::GetValue(struct GRFConfig *config) const
{
	/* GB doesn't work correctly with nbits == 32, so handle that case here. */
	if (this->num_bit == 32) return config->param[this->param_nr];
	return GB(config->param[this->param_nr], this->first_bit, this->num_bit);
}

/**
 * Set the value of this user-changeable parameter in the given config.
 * @param config The GRFConfig to set the value in.
 * @param value The new value.
 */
void GRFParameterInfo::SetValue(struct GRFConfig *config, uint32 value)
{
	/* SB doesn't work correctly with nbits == 32, so handle that case here. */
	if (this->num_bit == 32) {
		config->param[this->param_nr] = value;
	} else {
		SB(config->param[this->param_nr], this->first_bit, this->num_bit, value);
	}
	config->num_params = std::max<uint>(config->num_params, this->param_nr + 1);
	SetWindowDirty(WC_GAME_OPTIONS, WN_GAME_OPTIONS_NEWGRF_STATE);
}

/**
 * Finalize Action 14 info after file scan is finished.
 */
void GRFParameterInfo::Finalize()
{
	this->complete_labels = true;
	for (uint32 value = this->min_value; value <= this->max_value; value++) {
		if (!this->value_names.Contains(value)) {
			this->complete_labels = false;
			break;
		}
	}
}

/**
 * Update the palettes of the graphics from the config file.
 * Called when changing the default palette in advanced settings.
 * @param p1 Unused.
 * @return Always true.
 */
bool UpdateNewGRFConfigPalette(int32 p1)
{
	for (GRFConfig *c = _grfconfig_newgame; c != nullptr; c = c->next) c->SetSuitablePalette();
	for (GRFConfig *c = _grfconfig_static;  c != nullptr; c = c->next) c->SetSuitablePalette();
	for (GRFConfig *c = _all_grfs;          c != nullptr; c = c->next) c->SetSuitablePalette();
	return true;
}

/**
 * Get the data section size of a GRF.
 * @param f GRF.
 * @return Size of the data section or SIZE_MAX if the file has no separate data section.
 */
size_t GRFGetSizeOfDataSection(FILE *f)
{
	extern const byte _grf_cont_v2_sig[];
	static const uint header_len = 14;

	byte data[header_len];
	if (fread(data, 1, header_len, f) == header_len) {
		if (data[0] == 0 && data[1] == 0 && MemCmpT(data + 2, _grf_cont_v2_sig, 8) == 0) {
			/* Valid container version 2, get data section size. */
			size_t offset = ((size_t)data[13] << 24) | ((size_t)data[12] << 16) | ((size_t)data[11] << 8) | (size_t)data[10];
			if (offset >= 1 * 1024 * 1024 * 1024) {
				DEBUG(grf, 0, "Unexpectedly large offset for NewGRF");
				/* Having more than 1 GiB of data is very implausible. Mostly because then
				 * all pools in OpenTTD are flooded already. Or it's just Action C all over.
				 * In any case, the offsets to graphics will likely not work either. */
				return SIZE_MAX;
			}
			return header_len + offset;
		}
	}

	return SIZE_MAX;
}

/**
 * Calculate the MD5 sum for a GRF, and store it in the config.
 * @param config GRF to compute.
 * @param subdir The subdirectory to look in.
 * @return MD5 sum was successfully computed
 */
static bool CalcGRFMD5Sum(GRFConfig *config, Subdirectory subdir)
{
	FILE *f;
	Md5 checksum;
	uint8 buffer[1024];
	size_t len, size;

	/* open the file */
	f = FioFOpenFile(config->filename, "rb", subdir, &size);
	if (f == nullptr) return false;

	long start = ftell(f);
	size = std::min(size, GRFGetSizeOfDataSection(f));

	if (start < 0 || fseek(f, start, SEEK_SET) < 0) {
		FioFCloseFile(f);
		return false;
	}

	/* calculate md5sum */
	while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
		size -= len;
		checksum.Append(buffer, len);
	}
	checksum.Finish(config->ident.md5sum);

	FioFCloseFile(f);

	return true;
}


/**
 * Find the GRFID of a given grf, and calculate its md5sum.
 * @param config    grf to fill.
 * @param is_static grf is static.
 * @param subdir    the subdirectory to search in.
 * @return Operation was successfully completed.
 */
bool FillGRFDetails(GRFConfig *config, bool is_static, Subdirectory subdir)
{
	if (!FioCheckFileExists(config->filename, subdir)) {
		config->status = GCS_NOT_FOUND;
		return false;
	}

	/* Find and load the Action 8 information */
	LoadNewGRFFile(config, CONFIG_SLOT, GLS_FILESCAN, subdir);
	config->SetSuitablePalette();
	config->FinalizeParameterInfo();

	/* Skip if the grfid is 0 (not read) or if it is an internal GRF */
	if (config->ident.grfid == 0 || HasBit(config->flags, GCF_SYSTEM)) return false;

	if (is_static) {
		/* Perform a 'safety scan' for static GRFs */
		LoadNewGRFFile(config, CONFIG_SLOT, GLS_SAFETYSCAN, subdir);

		/* GCF_UNSAFE is set if GLS_SAFETYSCAN finds unsafe actions */
		if (HasBit(config->flags, GCF_UNSAFE)) return false;
	}

	return CalcGRFMD5Sum(config, subdir);
}


/**
 * Clear a GRF Config list, freeing all nodes.
 * @param config Start of the list.
 * @post \a config is set to \c nullptr.
 */
void ClearGRFConfigList(GRFConfig **config)
{
	GRFConfig *c, *next;
	for (c = *config; c != nullptr; c = next) {
		next = c->next;
		delete c;
	}
	*config = nullptr;
}


/**
 * Copy a GRF Config list
 * @param dst pointer to destination list
 * @param src pointer to source list values
 * @param init_only the copied GRF will be processed up to GLS_INIT
 * @return pointer to the last value added to the destination list
 */
GRFConfig **CopyGRFConfigList(GRFConfig **dst, const GRFConfig *src, bool init_only)
{
	/* Clear destination as it will be overwritten */
	ClearGRFConfigList(dst);
	for (; src != nullptr; src = src->next) {
		GRFConfig *c = new GRFConfig(*src);

		ClrBit(c->flags, GCF_INIT_ONLY);
		if (init_only) SetBit(c->flags, GCF_INIT_ONLY);

		*dst = c;
		dst = &c->next;
	}

	return dst;
}

/**
 * Removes duplicates from lists of GRFConfigs. These duplicates
 * are introduced when the _grfconfig_static GRFs are appended
 * to the _grfconfig on a newgame or savegame. As the parameters
 * of the static GRFs could be different that the parameters of
 * the ones used non-statically. This can result in desyncs in
 * multiplayers, so the duplicate static GRFs have to be removed.
 *
 * This function _assumes_ that all static GRFs are placed after
 * the non-static GRFs.
 *
 * @param list the list to remove the duplicates from
 */
static void RemoveDuplicatesFromGRFConfigList(GRFConfig *list)
{
	GRFConfig *prev;
	GRFConfig *cur;

	if (list == nullptr) return;

	for (prev = list, cur = list->next; cur != nullptr; prev = cur, cur = cur->next) {
		if (cur->ident.grfid != list->ident.grfid) continue;

		prev->next = cur->next;
		delete cur;
		cur = prev; // Just go back one so it continues as normal later on
	}

	RemoveDuplicatesFromGRFConfigList(list->next);
}

/**
 * Appends the static GRFs to a list of GRFs
 * @param dst the head of the list to add to
 */
void AppendStaticGRFConfigs(GRFConfig **dst)
{
	GRFConfig **tail = dst;
	while (*tail != nullptr) tail = &(*tail)->next;

	CopyGRFConfigList(tail, _grfconfig_static, false);
	RemoveDuplicatesFromGRFConfigList(*dst);
}

/**
 * Appends an element to a list of GRFs
 * @param dst the head of the list to add to
 * @param el the new tail to be
 */
void AppendToGRFConfigList(GRFConfig **dst, GRFConfig *el)
{
	GRFConfig **tail = dst;
	while (*tail != nullptr) tail = &(*tail)->next;
	*tail = el;

	RemoveDuplicatesFromGRFConfigList(*dst);
}


/** Reset the current GRF Config to either blank or newgame settings. */
void ResetGRFConfig(bool defaults)
{
	CopyGRFConfigList(&_grfconfig, _grfconfig_newgame, !defaults);
	AppendStaticGRFConfigs(&_grfconfig);
}


/**
 * Check if all GRFs in the GRF config from a savegame can be loaded.
 * @param grfconfig GrfConfig to check
 * @return will return any of the following 3 values:<br>
 * <ul>
 * <li> GLC_ALL_GOOD: No problems occurred, all GRF files were found and loaded
 * <li> GLC_COMPATIBLE: For one or more GRF's no exact match was found, but a
 *     compatible GRF with the same grfid was found and used instead
 * <li> GLC_NOT_FOUND: For one or more GRF's no match was found at all
 * </ul>
 */
GRFListCompatibility IsGoodGRFConfigList(GRFConfig *grfconfig)
{
	GRFListCompatibility res = GLC_ALL_GOOD;

	for (GRFConfig *c = grfconfig; c != nullptr; c = c->next) {
		const GRFConfig *f = FindGRFConfig(c->ident.grfid, FGCM_EXACT, c->ident.md5sum);
		if (f == nullptr || HasBit(f->flags, GCF_INVALID)) {
			char buf[256];

			/* 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, nullptr, c->version);
			if (f != nullptr) {
				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);
				if (!HasBit(c->flags, GCF_COMPATIBLE)) {
					/* Preserve original_md5sum after it has been assigned */
					SetBit(c->flags, GCF_COMPATIBLE);
					memcpy(c->original_md5sum, c->ident.md5sum, sizeof(c->original_md5sum));
				}

				/* Non-found has precedence over compatibility load */
				if (res != GLC_NOT_FOUND) res = GLC_COMPATIBLE;
				goto compatible_grf;
			}

			/* No compatible grf was found, mark it as disabled */
			md5sumToString(buf, lastof(buf), c->ident.md5sum);
			DEBUG(grf, 0, "NewGRF %08X (%s) not found; checksum %s", BSWAP32(c->ident.grfid), c->filename, buf);

			c->status = GCS_NOT_FOUND;
			res = GLC_NOT_FOUND;
		} else {
compatible_grf:
			DEBUG(grf, 1, "Loading GRF %08X from %s", BSWAP32(f->ident.grfid), f->filename);
			/* The filename could be the filename as in the savegame. As we need
			 * to load the GRF here, we need the correct filename, so overwrite that
			 * in any case and set the name and info when it is not set already.
			 * When the GCF_COPY flag is set, it is certain that the filename is
			 * already a local one, so there is no need to replace it. */
			if (!HasBit(c->flags, GCF_COPY)) {
				free(c->filename);
				c->filename = stredup(f->filename);
				memcpy(c->ident.md5sum, f->ident.md5sum, sizeof(c->ident.md5sum));
				c->name = f->name;
				c->info = f->name;
				c->error = nullptr;
				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.size(); i++) {
					if (f->param_info[i] == nullptr) {
						c->param_info.push_back(nullptr);
					} else {
						c->param_info.push_back(new GRFParameterInfo(*f->param_info[i]));
					}
				}
			}
		}
	}

	return res;
}

/** Helper for scanning for files with GRF as extension */
class GRFFileScanner : FileScanner {
	std::chrono::steady_clock::time_point next_update; ///< The next moment we do update the screen.
	uint num_scanned; ///< The number of GRFs we have scanned.

public:
	GRFFileScanner() : num_scanned(0)
	{
		this->next_update = std::chrono::steady_clock::now();
	}

	bool AddFile(const std::string &filename, size_t basepath_length, const std::string &tar_filename) override;

	/** Do the scan for GRFs. */
	static uint DoScan()
	{
		GRFFileScanner fs;
		int ret = fs.Scan(".grf", NEWGRF_DIR);
		/* The number scanned and the number returned may not be the same;
		 * duplicate NewGRFs and base sets are ignored in the return value. */
		_settings_client.gui.last_newgrf_count = fs.num_scanned;
		return ret;
	}
};

bool GRFFileScanner::AddFile(const std::string &filename, size_t basepath_length, const std::string &tar_filename)
{
	GRFConfig *c = new GRFConfig(filename.c_str() + basepath_length);

	bool added = true;
	if (FillGRFDetails(c, false)) {
		if (_all_grfs == nullptr) {
			_all_grfs = c;
		} else {
			/* Insert file into list at a position determined by its
			 * name, so the list is sorted as we go along */
			GRFConfig **pd, *d;
			bool stop = false;
			for (pd = &_all_grfs; (d = *pd) != nullptr; pd = &d->next) {
				if (c->ident.grfid == d->ident.grfid && memcmp(c->ident.md5sum, d->ident.md5sum, sizeof(c->ident.md5sum)) == 0) added = false;
				/* Because there can be multiple grfs with the same name, make sure we checked all grfs with the same name,
				 *  before inserting the entry. So insert a new grf at the end of all grfs with the same name, instead of
				 *  just after the first with the same name. Avoids doubles in the list. */
				if (strcasecmp(c->GetName(), d->GetName()) <= 0) {
					stop = true;
				} else if (stop) {
					break;
				}
			}
			if (added) {
				c->next = d;
				*pd = c;
			}
		}
	} else {
		added = false;
	}

	this->num_scanned++;

	const char *name = nullptr;
	if (c->name != nullptr) name = GetGRFStringFromGRFText(c->name);
	if (name == nullptr) name = c->filename;
	UpdateNewGRFScanStatus(this->num_scanned, name);
	VideoDriver::GetInstance()->GameLoopPause();

	if (!added) {
		/* File couldn't be opened, or is either not a NewGRF or is a
		 * 'system' NewGRF or it's already known, so forget about it. */
		delete c;
	}

	return added;
}

/**
 * Simple sorter for GRFS
 * @param c1 the first GRFConfig *
 * @param c2 the second GRFConfig *
 * @return true if the name of first NewGRF is before the name of the second.
 */
static bool GRFSorter(GRFConfig * const &c1, GRFConfig * const &c2)
{
	return strnatcmp(c1->GetName(), c2->GetName()) < 0;
}

/**
 * Really perform the scan for all NewGRFs.
 * @param callback The callback to call after the scanning is complete.
 */
void DoScanNewGRFFiles(NewGRFScanCallback *callback)
{
	ClearGRFConfigList(&_all_grfs);
	TarScanner::DoScan(TarScanner::NEWGRF);

	DEBUG(grf, 1, "Scanning for NewGRFs");
	uint num = GRFFileScanner::DoScan();

	DEBUG(grf, 1, "Scan complete, found %d files", num);
	if (num != 0 && _all_grfs != nullptr) {
		/* Sort the linked list using quicksort.
		 * For that we first have to make an array, then sort and
		 * then remake the linked list. */
		std::vector<GRFConfig *> to_sort;

		uint i = 0;
		for (GRFConfig *p = _all_grfs; p != nullptr; p = p->next, i++) {
			to_sort.push_back(p);
		}
		/* Number of files is not necessarily right */
		num = i;

		std::sort(to_sort.begin(), to_sort.end(), GRFSorter);

		for (i = 1; i < num; i++) {
			to_sort[i - 1]->next = to_sort[i];
		}
		to_sort[num - 1]->next = nullptr;
		_all_grfs = to_sort[0];

		NetworkAfterNewGRFScan();
	}

	/* Yes... these are the NewGRF windows */
	InvalidateWindowClassesData(WC_SAVELOAD, 0, true);
	InvalidateWindowData(WC_GAME_OPTIONS, WN_GAME_OPTIONS_NEWGRF_STATE, GOID_NEWGRF_RESCANNED, true);
	if (callback != nullptr) callback->OnNewGRFsScanned();

	DeleteWindowByClass(WC_MODAL_PROGRESS);
	SetModalProgress(false);
	MarkWholeScreenDirty();
}

/**
 * Scan for all NewGRFs.
 * @param callback The callback to call after the scanning is complete.
 */
void ScanNewGRFFiles(NewGRFScanCallback *callback)
{
	/* First set the modal progress. This ensures that it will eventually let go of the paint mutex. */
	SetModalProgress(true);
	/* Only then can we really start, especially by marking the whole screen dirty. Get those other windows hidden!. */
	MarkWholeScreenDirty();

	DoScanNewGRFFiles(callback);
}

/**
 * Find a NewGRF in the scanned list.
 * @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 nullptr.
 */
const GRFConfig *FindGRFConfig(uint32 grfid, FindGRFConfigMode mode, const uint8 *md5sum, uint32 desired_version)
{
	assert((mode == FGCM_EXACT) != (md5sum == nullptr));
	const GRFConfig *best = nullptr;
	for (const GRFConfig *c = _all_grfs; c != nullptr; c = c->next) {
		/* if md5sum is set, we look for an exact match and continue if not found */
		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 != nullptr || mode == FGCM_ANY) return c;
		/* Skip incompatible stuff, unless explicitly allowed */
		if (mode != FGCM_NEWEST && HasBit(c->flags, GCF_INVALID)) continue;
		/* 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 == nullptr || c->version > best->version) best = c;
	}

	return best;
}

/** Structure for UnknownGRFs; this is a lightweight variant of GRFConfig */
struct UnknownGRF : public GRFIdentifier {
	GRFTextWrapper name; ///< Name of the GRF.

	UnknownGRF() = default;
	UnknownGRF(const UnknownGRF &other) = default;
	UnknownGRF(UnknownGRF &&other) = default;
	UnknownGRF(uint32 grfid, const uint8 *_md5sum) : GRFIdentifier(grfid, _md5sum), name(new GRFTextList) {}
};

/**
 * Finds the name of a NewGRF in the list of names for unknown GRFs. An
 * unknown GRF is a GRF where the .grf is not found during scanning.
 *
 * The names are resolved via UDP calls to servers that should know the name,
 * though the replies may not come. This leaves "<Unknown>" as name, though
 * that shouldn't matter _very_ much as they need GRF crawler or so to look
 * up the GRF anyway and that works better with the GRF ID.
 *
 * @param grfid  the GRF ID part of the 'unique' GRF identifier
 * @param md5sum the MD5 checksum part of the 'unique' GRF identifier
 * @param create whether to create a new GRFConfig if the GRFConfig did not
 *               exist in the fake list of GRFConfigs.
 * @return The GRFTextWrapper of the name of the GRFConfig with the given GRF ID
 *         and MD5 checksum or nullptr when it does not exist and create is false.
 *         This value must NEVER be freed by the caller.
 */
GRFTextWrapper FindUnknownGRFName(uint32 grfid, uint8 *md5sum, bool create)
{
	static std::vector<UnknownGRF> unknown_grfs;

	for (const auto &grf : unknown_grfs) {
		if (grf.grfid == grfid) {
			if (memcmp(md5sum, grf.md5sum, sizeof(grf.md5sum)) == 0) return grf.name;
		}
	}

	if (!create) return nullptr;

	unknown_grfs.emplace_back(grfid, md5sum);
	UnknownGRF &grf = unknown_grfs.back();

	AddGRFTextToList(grf.name, UNKNOWN_GRF_NAME_PLACEHOLDER);

	return grf.name;
}

/**
 * Retrieve a NewGRF from the current config by its grfid.
 * @param grfid grf to look for.
 * @param mask  GRFID mask to allow for partial matching.
 * @return The grf config, if it exists, else \c nullptr.
 */
GRFConfig *GetGRFConfig(uint32 grfid, uint32 mask)
{
	GRFConfig *c;

	for (c = _grfconfig; c != nullptr; c = c->next) {
		if ((c->ident.grfid & mask) == (grfid & mask)) return c;
	}

	return nullptr;
}


/** Build a string containing space separated parameter values, and terminate */
char *GRFBuildParamList(char *dst, const GRFConfig *c, const char *last)
{
	uint i;

	/* Return an empty string if there are no parameters */
	if (c->num_params == 0) return strecpy(dst, "", last);

	for (i = 0; i < c->num_params; i++) {
		if (i > 0) dst = strecpy(dst, " ", last);
		dst += seprintf(dst, last, "%d", c->param[i]);
	}
	return dst;
}

/** Base GRF ID for OpenTTD's base graphics GRFs. */
static const uint32 OPENTTD_GRAPHICS_BASE_GRF_ID = BSWAP32(0xFF4F5400);

/**
 * Search a textfile file next to this NewGRF.
 * @param type The type of the textfile to search for.
 * @return The filename for the textfile, \c nullptr otherwise.
 */
const char *GRFConfig::GetTextfile(TextfileType type) const
{
	return ::GetTextfile(type, NEWGRF_DIR, this->filename);
}