diff: string__format bug fix

[Fergus Henderson]

library/string.m:
	Fix a bug in string__format: it was not reporting an error
	in the case where the argument list had more elements
	than was appropriate for the format string.

tests/general/Mmakefile:
tests/general/string_format_test_2.m:
tests/general/string_format_test_2.exp:
tests/general/string_format_test_3.m:
tests/general/string_format_test_3.exp:
	Test cases for the above-mentioned bug fix.

Index: library/string.m
===================================================================
RCS file: /home/mercury1/repository/mercury/library/string.m,v
retrieving revision 1.106
diff -u -r1.106 string.m
--- string.m	1998/08/24 04:45:28	1.106
+++ string.m	1998/10/27 15:04:01
@@ -815,7 +815,13 @@
 %	is not efficient.  Instead, many short strings are added to the front
 %	of a (long) and growing string.
 %
-string__format_2([], _, "").
+string__format_2([], Vars_in, Result) :-
+	( Vars_in = [] ->
+		Result = ""
+	;
+		error(
+	"string__format: argument list has more elements than format string")
+	).
 string__format_2([Achar|As], Vars_in, Ostring) :-
 	(
 		Achar = '%'
@@ -833,7 +839,8 @@
 				string__format_2(As_out, Vars_out, String_2),
 				string__append(String_1, String_2, Ostring)
 			;
-				error("string__format: Too few variables.")
+				error(
+	"string__format: argument list has fewer elements than format string")
 			)
 		)
 	;
Index: tests/general/Mmakefile
===================================================================
RCS file: /home/mercury1/repository/tests/general/Mmakefile,v
retrieving revision 1.23
diff -u -r1.23 Mmakefile
--- Mmakefile	1998/09/21 13:18:01	1.23
+++ Mmakefile	1998/10/27 15:13:51
@@ -57,6 +57,8 @@
 		semidet_map \
 		set_test \
 		string_format_test \
+		string_format_test_2 \
+		string_format_test_3 \
 		string_test \
 		string_test_2 \
 		univ \
@@ -66,6 +68,11 @@
 # (i.e. tabling) and tabling is not yet implemented for non-gc grades.
 NOT_WORKING =	dnf
 
+#-----------------------------------------------------------------------------#
+#
+# Some test cases need special handling.
+#
+
 # mode_inf and mode_inf_bug need to be compiled with `--infer-all'.
 MCFLAGS-mode_inf = --infer-all
 MCFLAGS-mode_inf_bug = --infer-all
@@ -83,6 +90,15 @@
 # tracking it down.
 MLFLAGS-string_test = --no-strip
 
+# string_format_test_2 and string__format_test_3 are expected to fail
+# (string__format should call error/1 for these test cases)
+# so we need to ignore the exit status (hence the leading `-')
+string_format_test_2.out: string_format_test_2
+        -./string_format_test_2 > string_format_test_2.out 2>&1;
+string_format_test_3.out: string_format_test_3
+        -./string_format_test_3 > string_format_test_2.out 2>&1;
+
+#-----------------------------------------------------------------------------#
 
 DEPENDS=$(PROGS:%=%.depend)
 OUTS=	$(PROGS:%=%.out)
Index: tests/general/string_format_test_2.exp
===================================================================
RCS file: string_format_test_2.exp
diff -N string_format_test_2.exp
--- /dev/null	Wed Oct 28 02:21:38 1998
+++ string_format_test_2.exp	Wed Oct 28 02:16:15 1998
@@ -0,0 +1,2 @@
+Software error: string__format: argument list has more elements than format string
+Stack dump not available in this grade.
Index: tests/general/string_format_test_2.m
===================================================================
RCS file: string_format_test_2.m
diff -N string_format_test_2.m
--- /dev/null	Wed Oct 28 02:21:38 1998
+++ string_format_test_2.m	Wed Oct 28 02:14:33 1998
@@ -0,0 +1,13 @@
+:- module string_format_test_2.
+
+:- interface.
+
+:- import_module io.
+
+:- pred main(io__state::di, io__state::uo) is det.
+
+:- implementation.
+
+:- import_module list, string.
+
+main --> io__format("foo\n", [i(42)]).
Index: tests/general/string_format_test_3.exp
===================================================================
RCS file: string_format_test_3.exp
diff -N string_format_test_3.exp
--- /dev/null	Wed Oct 28 02:21:38 1998
+++ string_format_test_3.exp	Wed Oct 28 02:29:31 1998
@@ -0,0 +1,2 @@
+Software error: string__format: argument list has fewer elements than format string
+Stack dump not available in this grade.
Index: tests/general/string_format_test_3.m
===================================================================
RCS file: string_format_test_3.m
diff -N string_format_test_3.m
--- /dev/null	Wed Oct 28 02:21:38 1998
+++ string_format_test_3.m	Wed Oct 28 02:14:41 1998
@@ -0,0 +1,13 @@
+:- module string_format_test_3.
+
+:- interface.
+
+:- import_module io.
+
+:- pred main(io__state::di, io__state::uo) is det.
+
+:- implementation.
+
+:- import_module list, string.
+
+main --> io__format("%s\n", []).

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.