Commit 81a456b28f195b4d4e48aff03359aaa68ae6e3b4
2023-01-04T22:41:34
* src/base/ftobjs.c (FT_Request_Metrics): Avoid division by zero. The division-by-zero might happen in broken fonts (see #1194). Instead of returning a huge number from FT_DivFix and failing to scale later, we now bail immediately.
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diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
index 7f1f063..4ef702a 100644
--- a/src/base/ftobjs.c
+++ b/src/base/ftobjs.c
@@ -3280,34 +3280,49 @@
scaled_h = FT_REQUEST_HEIGHT( req );
/* determine scales */
- if ( req->width )
+ if ( req->height || !req->width )
{
- metrics->x_scale = FT_DivFix( scaled_w, w );
-
- if ( req->height )
+ if ( h == 0 )
{
- metrics->y_scale = FT_DivFix( scaled_h, h );
-
- if ( req->type == FT_SIZE_REQUEST_TYPE_CELL )
- {
- if ( metrics->y_scale > metrics->x_scale )
- metrics->y_scale = metrics->x_scale;
- else
- metrics->x_scale = metrics->y_scale;
- }
+ FT_ERROR(( "FT_Request_Metrics: Divide by zero\n" ));
+ error = FT_ERR( Divide_By_Zero );
+ goto Exit;
}
- else
+
+ metrics->y_scale = FT_DivFix( scaled_h, h );
+ }
+
+ if ( req->width )
+ {
+ if ( w == 0 )
{
- metrics->y_scale = metrics->x_scale;
- scaled_h = FT_MulDiv( scaled_w, h, w );
+ FT_ERROR(( "FT_Request_Metrics: Divide by zero\n" ));
+ error = FT_ERR( Divide_By_Zero );
+ goto Exit;
}
+
+ metrics->x_scale = FT_DivFix( scaled_w, w );
}
else
{
- metrics->x_scale = metrics->y_scale = FT_DivFix( scaled_h, h );
+ metrics->x_scale = metrics->y_scale;
scaled_w = FT_MulDiv( scaled_h, w, h );
}
+ if ( !req->height )
+ {
+ metrics->y_scale = metrics->x_scale;
+ scaled_h = FT_MulDiv( scaled_w, h, w );
+ }
+
+ if ( req->type == FT_SIZE_REQUEST_TYPE_CELL )
+ {
+ if ( metrics->y_scale > metrics->x_scale )
+ metrics->y_scale = metrics->x_scale;
+ else
+ metrics->x_scale = metrics->y_scale;
+ }
+
Calculate_Ppem:
/* calculate the ppems */
if ( req->type != FT_SIZE_REQUEST_TYPE_NOMINAL )