kernel: raise error if eager float literal conversion fails

Fixes gap-system#1105

src/intrprtr.c

@@ -1804,7 +1804,10 @@ static Obj ConvertFloatLiteralEager(Obj str)
  SET_LEN_STRING(str, len - 2);
  chars[len - 2] = '\0';
  }
- return CALL_2ARGS(CONVERT_FLOAT_LITERAL_EAGER, str, ObjsChar[(UInt)mark]);
+ Obj res = CALL_2ARGS(CONVERT_FLOAT_LITERAL_EAGER, str, ObjsChar[(UInt)mark]);
+ if (res == Fail)
+ ErrorQuit("failed to convert float literal", 0, 0);
+ return res;
 }
 
 void IntrFloatExpr (

tst/testinstall/float.tst

@@ -237,6 +237,27 @@ false
 gap> EqFloat(0.0,0.0/0.0);
 false
 
+#
+# float literals in the REPL
+#
+gap> 1.1;
+1.1
+gap> 1.1_;
+1.1
+gap> 1.x1;
+Syntax error: Badly formed number in stream:1
+1.x1;
+ ^
+gap> 1.1xx;
+Syntax error: Badly formed number in stream:1
+1.1xx;
+ ^
+
+# The following is potentially correct, *if* there is a conversion handler for
+# 'x' installed, which normally isn't the case.
+gap> 1.1x;
+Error, failed to convert float literal
+
 #
 # float literal expressions in functions
 #

tst/testinstall/longnumber.tst

@@ -180,7 +180,7 @@ int in stream:1
 .q;
 ^
 gap> .0n;
-fail
+Error, failed to convert float literal
 gap> .0q;
 Syntax error: Badly Formed Number: need at least one digit in the exponent in \
 stream:1