(svn r27607) [1.6] -Backport from trunk:

- Fix: Compilation and optimisation issues with GCC6 (r27606, r27605, r27595)
- Fix: Compilation with --disable-network [FS#6481] (r27602)
- Fix: [NewGRF] shift-and-add-divide/modulo varadjusts use signed division/modulo (r27600)
- Fix: Company 0 could accept engine previews before they were offered (r27598)

config.lib

@@ -1380,7 +1380,7 @@ make_compiler_cflags() {
 			flags="$flags -Wnon-virtual-dtor"
 		fi
 
-		if [ $cc_version -ge 43 ]; then
+		if [ $cc_version -ge 43 ] && [ $cc_version -lt 60 ]; then
 			# Use gnu++0x mode so static_assert() is available.
 			# Don't use c++0x, it breaks mingw (with gcc 4.4.0).
 			cxxflags="$cxxflags -std=gnu++0x"
@@ -1401,6 +1401,12 @@ make_compiler_cflags() {
 			flags="$flags -Wno-free-nonheap-object"
 		fi
 
+		if [ $cc_version -ge 60 ]; then
+			# -flifetime-dse=2 (default since GCC 6) doesn't play
+			# well with our custom pool item allocator
+			cxxflags="$cxxflags -flifetime-dse=1 -std=gnu++14"
+		fi
+
 		if [ "$enable_lto" != "0" ]; then
 			# GCC 4.5 outputs '%{flto}', GCC 4.6 outputs '%{flto*}'
 			has_lto=`$1 -dumpspecs | grep '\%{flto'`

src/3rdparty/squirrel/squirrel/sqapi.cpp

@@ -798,7 +798,8 @@ SQRESULT sq_setdelegate(HSQUIRRELVM v,SQInteger idx)
 	switch(type) {
 	case OT_TABLE:
 		if(type(mt) == OT_TABLE) {
-			if(!_table(self)->SetDelegate(_table(mt))) return sq_throwerror(v, "delagate cycle"); v->Pop();}
+			if(!_table(self)->SetDelegate(_table(mt))) return sq_throwerror(v, "delagate cycle");
+			v->Pop();}
 		else if(type(mt)==OT_NULL) {
 			_table(self)->SetDelegate(NULL); v->Pop(); }
 		else return sq_aux_invalidtype(v,type);

src/engine.cpp

@@ -85,6 +85,7 @@ Engine::Engine(VehicleType type, EngineID base)
 	this->type = type;
 	this->grf_prop.local_id = base;
 	this->list_position = base;
+	this->preview_company = INVALID_COMPANY;
 
 	/* Check if this base engine is within the original engine data range */
 	if (base >= _engine_counts[type]) {
@@ -902,7 +903,7 @@ CommandCost CmdSetVehicleVisibility(TileIndex tile, DoCommandFlag flags, uint32
 CommandCost CmdWantEnginePreview(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 {
 	Engine *e = Engine::GetIfValid(p1);
-	if (e == NULL || e->preview_company != _current_company) return CMD_ERROR;
+	if (e == NULL || !(e->flags & ENGINE_EXCLUSIVE_PREVIEW) || e->preview_company != _current_company) return CMD_ERROR;
 
 	if (flags & DC_EXEC) AcceptEnginePreview(p1, _current_company);
 

src/newgrf_spritegroup.cpp

@@ -204,8 +204,8 @@ static U EvalAdjustT(const DeterministicSpriteGroupAdjust *adjust, ScopeResolver
 	if (adjust->type != DSGA_TYPE_NONE) value += (S)adjust->add_val;
 
 	switch (adjust->type) {
-		case DSGA_TYPE_DIV:  value /= (S)adjust->divmod_val; break;
+		case DSGA_TYPE_DIV:  value = (S)value / (S)adjust->divmod_val; break;
-		case DSGA_TYPE_MOD:  value %= (U)adjust->divmod_val; break;
+		case DSGA_TYPE_MOD:  value = (S)value % (S)adjust->divmod_val; break;
 		case DSGA_TYPE_NONE: break;
 	}
 

src/strings.cpp

@@ -35,7 +35,9 @@
 #include "window_func.h"
 #include "debug.h"
 #include "game/game_text.hpp"
-#include "network/network_content_gui.h"
+#ifdef ENABLE_NETWORK
+#	include "network/network_content_gui.h"
+#endif /* ENABLE_NETWORK */
 #include <stack>
 
 #include "table/strings.h"
@@ -1815,7 +1817,9 @@ bool ReadLanguagePack(const LanguageMetadata *lang)
 	SortIndustryTypes();
 	BuildIndustriesLegend();
 	SortNetworkLanguages();
+#ifdef ENABLE_NETWORK
 	BuildContentTypeStringList();
+#endif /* ENABLE_NETWORK */
 	InvalidateWindowClassesData(WC_BUILD_VEHICLE);      // Build vehicle window.
 	InvalidateWindowClassesData(WC_TRAINS_LIST);        // Train group window.
 	InvalidateWindowClassesData(WC_ROADVEH_LIST);       // Road vehicle group window.