Fix floating point exception caused by multiplication overflow turning to zero in prod variable

dkjsone · dkjsone · commit 2ec6c18b9a0e · 2025-10-24T16:40:22.000+08:00
diff --git a/libsrc/var.c b/libsrc/var.c
@@ -485,6 +485,8 @@ NC_var_shape(NC_var *varp, const NC_dimarray *dims)
       /*if(!(shp == varp->shape && IS_RECVAR(varp)))*/
       if( shp != NULL && (shp != varp->shape || !IS_RECVAR(varp)))
 		{
+          if(product <= 0)
+            return NC_ERANGE;
           if( ((off_t)(*shp)) <= OFF_T_MAX / product )
 			{
               product *= (*shp > 0 ? (off_t)*shp : 1);

Original file line number	Diff line number	Diff line change
`@@ -485,6 +485,8 @@ NC_var_shape(NC_var varp, const NC_dimarray dims)`
`485`	`485`	`/if(!(shp == varp->shape && IS_RECVAR(varp)))/`
`486`	`486`	`if( shp != NULL && (shp != varp->shape \|\| !IS_RECVAR(varp)))`
`487`	`487`	`{`
	`488`	`+ if(product <= 0)`
	`489`	`+ return NC_ERANGE;`
`488`	`490`	`if( ((off_t)(*shp)) <= OFF_T_MAX / product )`
`489`	`491`	`{`
`490`	`492`	`product = (shp > 0 ? (off_t)*shp : 1);`