18013: Handle test of (( float == 0.0)) properly

2 files changed, 8 insertions, 6 deletions

diff --git a/Src/builtin.c b/Src/builtin.c
index f9f65e961..530bba8c8 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -4759,13 +4759,14 @@ bin_ttyctl(char *name, char **argv, Options ops, int func)
 int
 bin_let(char *name, char **argv, Options ops, int func)
 {
-    zlong val = 0;
+    mnumber val = zero_mnumber;
 
     while (*argv)
-	val = mathevali(*argv++);
+	val = matheval(*argv++);
     /* Errors in math evaluation in let are non-fatal. */
     errflag = 0;
-    return !val;
+    /* should test for fabs(val.u.d) < epsilon? */
+    return (val.type == MN_INTEGER) ? val.u.l == 0 : val.u.d == 0.0;
 }
 
 /* umask command.  umask may be specified as octal digits, or in the  *
diff --git a/Src/exec.c b/Src/exec.c
index 76ca437f4..978470251 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -3087,7 +3087,7 @@ static int
 execarith(Estate state, int do_exec)
 {
     char *e;
-    zlong val = 0;
+    mnumber val = zero_mnumber;
     int htok = 0;
 
     if (isset(XTRACE)) {
@@ -3101,7 +3101,7 @@ execarith(Estate state, int do_exec)
     if (isset(XTRACE))
 	fprintf(xtrerr, " %s", e);
 
-    val = mathevali(e);
+    val = matheval(e);
 
     cmdpop();
 
@@ -3110,7 +3110,8 @@ execarith(Estate state, int do_exec)
 	fflush(xtrerr);
     }
     errflag = 0;
-    return !val;
+    /* should test for fabs(val.u.d) < epsilon? */
+    return (val.type == MN_INTEGER) ? val.u.l == 0 : val.u.d == 0.0;
 }
 
 /* perform time ... command */