Fix passing invalid rnam values to records

src/error.c

@@ -512,6 +512,19 @@ void ErrorMayQuit(const Char * msg, Int arg1, Int arg2)
     Panic("ErrorMayQuit must not return");
 }
 
+/****************************************************************************
+**
+*F  GetValidRNam( <funcname>, <rnam> ) . check if <rnam> is a valid prec rnam
+*/
+UInt GetValidRNam(const char * funcname, Obj rnam)
+{
+    RequirePositiveSmallInt(funcname, rnam, "<rnam>");
+    UInt val = INT_INTOBJ(rnam);
+    RequireArgumentCondition(funcname, rnam, IS_VALID_RNAM(val),
+                             "must be a valid rnam");
+    return val;
+}
+
 /****************************************************************************
 **
 *F  CheckIsPossList( <desc>, <poss> ) . . . . . . . . . . check for poss list

src/error.h

@@ -285,6 +285,14 @@ GetPositiveSmallIntEx(const char * funcname, Obj op, const char * argname)
 #define GetPositiveSmallInt(funcname, op)                                    \
     GetPositiveSmallIntEx(funcname, op, NICE_ARGNAME(op))
 
+/****************************************************************************
+**
+*F  GetValidRNam
+**
+**  Check if <rnam> is a valid prec rnam. Error if not.
+**  Returns the rnam, when it is valid.
+*/
+UInt GetValidRNam(const char * funcname, Obj rnam);
 
 /****************************************************************************
 **

src/records.c

@@ -33,6 +33,11 @@ static Obj HashRNam;
 
 static Obj NamesRNam;
 
+extern inline Int IS_VALID_RNAM(UInt rnam)
+{
+    return rnam != 0 && rnam <= LEN_PLIST(NamesRNam);
+}
+
 extern inline Obj NAME_RNAM(UInt rnam)
 {
     return ELM_PLIST(NamesRNam, rnam);
@@ -334,7 +339,7 @@ static Obj ElmRecOper;
 
 static Obj ElmRecHandler(Obj self, Obj rec, Obj rnam)
 {
-    return ELM_REC( rec, INT_INTOBJ(rnam) );
+    return ELM_REC(rec, GetValidRNam("Record Element", rnam));
 }
 
 static Obj ElmRecError(Obj rec, UInt rnam)
@@ -368,7 +373,8 @@ static Obj IsbRecOper;
 
 static Obj IsbRecHandler(Obj self, Obj rec, Obj rnam)
 {
-    return (ISB_REC( rec, INT_INTOBJ(rnam) ) ? True : False);
+    return (ISB_REC(rec, GetValidRNam("Record IsBound", rnam)) ? True
+                                                               : False);
 }
 
 static Int IsbRecError(Obj rec, UInt rnam)
@@ -397,7 +403,7 @@ static Obj AssRecOper;
 
 static Obj AssRecHandler(Obj self, Obj rec, Obj rnam, Obj obj)
 {
-    ASS_REC( rec, INT_INTOBJ(rnam), obj );
+    ASS_REC(rec, GetValidRNam("Record Assignment", rnam), obj);
     return 0;
 }
 
@@ -426,7 +432,7 @@ static Obj UnbRecOper;
 
 static Obj UnbRecHandler(Obj self, Obj rec, Obj rnam)
 {
-    UNB_REC( rec, INT_INTOBJ(rnam) );
+    UNB_REC(rec, GetValidRNam("Record Unbind", rnam));
     return 0;
 }
 

src/records.h

@@ -18,11 +18,22 @@
 
 #include "objects.h"
 
+/****************************************************************************
+**
+*F  IS_VALID_RNAM(<rnam>) . . . . . . . . . . . . .  check if <rnam> is valid
+**
+**  'IS_VALID_RNAM' returns if <rnam> is a valid record name.
+*/
+Int IS_VALID_RNAM(UInt rnam);
+
 /****************************************************************************
 **
 *F  NAME_RNAM(<rnam>) . . . . . . . . . . .  name for a record name as an Obj
 **
 **  'NAME_RNAM' returns the name (as an Obj) for the record name <rnam>.
+**
+**  This function should only be called for valid RNAMs (this can be checked
+**  with IS_VALID_RNAM).
 */
 Obj NAME_RNAM(UInt rnam);
 

tst/testinstall/recordname.tst

@@ -71,4 +71,97 @@ Syntax error: Identifiers in GAP must consist of at most 1023 characters. in s\
 tream:2
 aaaxyz := 1; # 1024 chars
  ^^^^^
+gap> r := rec(y := 2);
+rec( y := 2 )
+gap> \.(r, RNamObj("y"));
+2
+gap> \.(r, RNamObj("x"));
+Error, Record Element: '<rec>.x' must have an assigned value
+gap> \.(r, 0);
+Error, Record Element: <rnam> must be a positive small integer (not the intege\
+r 0)
+gap> \.(r, -1);
+Error, Record Element: <rnam> must be a positive small integer (not the intege\
+r -1)
+gap> \.(r, 2^1000);
+Error, Record Element: <rnam> must be a positive small integer (not a large po\
+sitive integer)
+gap> \.(r, "a");
+Error, Record Element: <rnam> must be a positive small integer (not a list (st\
+ring))
+gap> \.(r, 1000000);
+Error, Record Element: <rnam> must be a valid rnam (not the integer 1000000)
+
+##
+gap> IsBound\.(r, RNamObj("y"));
+true
+gap> IsBound\.(r, RNamObj("x"));
+false
+gap> IsBound\.(r, 0);
+Error, Record IsBound: <rnam> must be a positive small integer (not the intege\
+r 0)
+gap> IsBound\.(r, -1);
+Error, Record IsBound: <rnam> must be a positive small integer (not the intege\
+r -1)
+gap> IsBound\.(r, 2^1000);
+Error, Record IsBound: <rnam> must be a positive small integer (not a large po\
+sitive integer)
+gap> IsBound\.(r, "a");
+Error, Record IsBound: <rnam> must be a positive small integer (not a list (st\
+ring))
+gap> IsBound\.(r, 1000000);
+Error, Record IsBound: <rnam> must be a valid rnam (not the integer 1000000)
+
+##
+gap> r;
+rec( y := 2 )
+gap> Unbind\.(r, RNamObj("y"));
+gap> r;
+rec(  )
+gap> Unbind\.(r, RNamObj("y"));
+gap> r;
+rec(  )
+gap> Unbind\.(r, RNamObj("x"));
+gap> Unbind\.(r, 0);
+Error, Record Unbind: <rnam> must be a positive small integer (not the integer\
+ 0)
+gap> Unbind\.(r, -1);
+Error, Record Unbind: <rnam> must be a positive small integer (not the integer\
+ -1)
+gap> Unbind\.(r, 2^1000);
+Error, Record Unbind: <rnam> must be a positive small integer (not a large pos\
+itive integer)
+gap> Unbind\.(r, "a");
+Error, Record Unbind: <rnam> must be a positive small integer (not a list (str\
+ing))
+gap> Unbind\.(r, 1000000);
+Error, Record Unbind: <rnam> must be a valid rnam (not the integer 1000000)
+
+##
+gap> r;
+rec(  )
+gap> \.\:\=(r,RNamObj("y"), 2);
+gap> r;
+rec( y := 2 )
+gap> \.\:\=(r,RNamObj("y"), 4);
+gap> r;
+rec( y := 4 )
+gap> \.\:\=(r,RNamObj("x"), 5);
+gap> r;
+rec( x := 5, y := 4 )
+gap> \.\:\=(r, 0, 1);
+Error, Record Assignment: <rnam> must be a positive small integer (not the int\
+eger 0)
+gap> \.\:\=(r, -1, 1);
+Error, Record Assignment: <rnam> must be a positive small integer (not the int\
+eger -1)
+gap> \.\:\=(r, 2^1000, 1);
+Error, Record Assignment: <rnam> must be a positive small integer (not a large\
+ positive integer)
+gap> \.\:\=(r, "a", 1);
+Error, Record Assignment: <rnam> must be a positive small integer (not a list \
+(string))
+gap> \.\:\=(r, 1000000, 1);
+Error, Record Assignment: <rnam> must be a valid rnam (not the integer 1000000\
+)
 gap> STOP_TEST( "recordname.tst", 1);