Added an integer overflow check on literal values in the script parser

- When attempting to use a value greater than INT_MAX or smaller than
  INT_MIN (about +/- 2 billions), an error message will be shown and
  script execution will be aborted.
- Corrected some scripts that were attempting to use such values.
- Fixed some possible issues when using literal negative values in
  scripts.
Thanks to Ind for his help on this issue (figuring it out and fixing it)

Signed-off-by: Haru <haru@dotalux.com>

5 files changed, 26 insertions, 17 deletions

diff --git a/doc/script_commands.txt b/doc/script_commands.txt
index 2e8afe5dd..b10c7aef0 100644
--- a/doc/script_commands.txt
+++ b/doc/script_commands.txt
@@ -404,7 +404,9 @@ are otherwise identical. Writing a number like '0x<hex digits>' will make
 it recognized as a hexadecimal value. Notice that 0x10 is equal to 16. 
 Also notice that if you try to 'mes 0x10' it will print '16'.
 
-This is not used much, but it pays to know about it.
+Number values can't exceed the limits of an integer variable: Any number
+greater than INT_MAX (2147483647) or smaller than INT_MIN (-2147483648) will
+not be recognized.
 
 Variables
 ---------
diff --git a/npc/pre-re/guides/guides_lighthalzen.txt b/npc/pre-re/guides/guides_lighthalzen.txt
index c9fb40b5b..466182cd9 100644
--- a/npc/pre-re/guides/guides_lighthalzen.txt
+++ b/npc/pre-re/guides/guides_lighthalzen.txt
@@ -80,7 +80,7 @@ lighthalzen,207,310,5	script	Guide#lhz::LhzGuide	852,{
 					mes "activity, or if you have any";
 					mes "problems whatsoever.";
 					if (.@compass_check)
-						viewpoint 1,236,276,4,0x99FFFFF;
+						viewpoint 1,236,276,4,0x99FFFF;
 					break;
 				case 4:
 					mes "[Lighthalzen Guide]";
diff --git a/npc/quests/quests_lighthalzen.txt b/npc/quests/quests_lighthalzen.txt
index d67e79c78..1085774e0 100644
--- a/npc/quests/quests_lighthalzen.txt
+++ b/npc/quests/quests_lighthalzen.txt
@@ -4472,10 +4472,10 @@ lighthalzen,346,263,3	script	Elder#lhz	846,{
 				mes "you must search should";
 				mes "be clear to you now! Don't";
 				mes "forget these placemarks!";
-				viewpoint 1,104,282,1,0xFF99FF33;
-				viewpoint 1,105,282,2,0xFF99FF33;
-				viewpoint 1,104,281,3,0xFF99FF33;
-				viewpoint 1,105,281,4,0xFF99FF33;
+				viewpoint 1,104,282,1,0x99FF33;
+				viewpoint 1,105,282,2,0x99FF33;
+				viewpoint 1,104,281,3,0x99FF33;
+				viewpoint 1,105,281,4,0x99FF33;
 				next;
 				mes "[Elder]";
 				mes "Good luck, youngster.";
diff --git a/npc/quests/quests_moscovia.txt b/npc/quests/quests_moscovia.txt
index bf6177bed..9ef4e6481 100644
--- a/npc/quests/quests_moscovia.txt
+++ b/npc/quests/quests_moscovia.txt
@@ -10970,20 +10970,20 @@ treasure01,24,39,0	script	Old Bed#rus38	111,{
 		mes "...?! What is this?";
 		next;
 		mes "- There is a scar on the sheet that seems to have the location !! -";
-		viewpoint 1,165,58,1,0xFFFF0000;
-		viewpoint 1,61,183,2,0xFFFF0000;
-		viewpoint 1,98,118,3,0xFFFF0000;
-		viewpoint 1,27,115,4,0xFFFF0000;
+		viewpoint 1,165,58,1,0xFF0000;
+		viewpoint 1,61,183,2,0xFF0000;
+		viewpoint 1,98,118,3,0xFF0000;
+		viewpoint 1,27,115,4,0xFF0000;
 		next;
 		mes "["+ strcharinfo(0) +"]";
 		mes "...This may be?!";
 		next;
 		mes "[Voice unidentified]";
 		mes "Who is there!?";
-		viewpoint 2,165,58,1,0xFF00FF00;
-		viewpoint 2,61,183,2,0xFF00FF00;
-		viewpoint 2,98,118,3,0xFF00FF00;
-		viewpoint 2,27,115,4,0xFF00FF00;
+		viewpoint 2,165,58,1,0x00FF00;
+		viewpoint 2,61,183,2,0x00FF00;
+		viewpoint 2,98,118,3,0x00FF00;
+		viewpoint 2,27,115,4,0x00FF00;
 		emotion 23,1;
 		next;
 		mes "["+ strcharinfo(0) +"]";
@@ -11824,4 +11824,4 @@ pay_dun04,163,186,0	script	Ghost Tree#rus45	111,{
 		close;
 	}
 	end;
-}
\ No newline at end of file
+}
diff --git a/src/map/script.c b/src/map/script.c
index bad40b948..754cf6dd5 100644
--- a/src/map/script.c
+++ b/src/map/script.c
@@ -1006,7 +1006,7 @@ const char* parse_variable(const char* p) {
  *------------------------------------------*/
 const char* parse_simpleexpr(const char *p)
 {
-	int i;
+	long long i;
 	p=script->skip_space(p);
 
 	if(*p==';' || *p==',')
@@ -1031,7 +1031,14 @@ const char* parse_simpleexpr(const char *p)
 	} else if(ISDIGIT(*p) || ((*p=='-' || *p=='+') && ISDIGIT(p[1]))){
 		char *np;
 		while(*p == '0' && ISDIGIT(p[1])) p++;
-		i=strtoul(p,&np,0);
+		i=strtoll(p,&np,0);
+		if( i < INT_MIN ) {
+			i = INT_MIN;
+			disp_error_message("parse_simpleexpr: underflow detected, capping value to INT_MIN",p);
+		} else if( i > INT_MAX ) {
+			i = INT_MAX;
+			disp_error_message("parse_simpleexpr: overflow detected, capping value to INT_MAX",p);
+		}
 		add_scripti(i);
 		p=np;
 	} else if(*p=='"'){