Check last error after query to FontMetrics to prevent panic (fixes #309

)
gographics · Apr 3, 2024 · 31e5640 · 31e5640
1 parent 734ab12
commit 31e5640
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Showing 2 changed files with 24 additions and 0 deletions.
diff --git a/imagick/magick_wand.go b/imagick/magick_wand.go
@@ -129,6 +129,9 @@ func (mw *MagickWand) QueryFontMetrics(dw *DrawingWand, textLine string) *FontMe
 	cstext := C.CString(textLine)
 	defer C.free(unsafe.Pointer(cstext))
 	cdoubles := C.MagickQueryFontMetrics(mw.mw, dw.dw, cstext)
+	if err := mw.GetLastError(); err != nil {
+		return nil
+	}
 	runtime.KeepAlive(mw)
 	runtime.KeepAlive(dw)
 	defer relinquishMemory(unsafe.Pointer(cdoubles))
@@ -141,6 +144,9 @@ func (mw *MagickWand) QueryMultilineFontMetrics(dw *DrawingWand, textParagraph s
 	cstext := C.CString(textParagraph)
 	defer C.free(unsafe.Pointer(cstext))
 	cdoubles := C.MagickQueryMultilineFontMetrics(mw.mw, dw.dw, cstext)
+	if err := mw.GetLastError(); err != nil {
+		return nil
+	}
 	runtime.KeepAlive(mw)
 	runtime.KeepAlive(dw)
 	defer relinquishMemory(unsafe.Pointer(cdoubles))

diff --git a/imagick/magick_wand_test.go b/imagick/magick_wand_test.go
@@ -101,6 +101,24 @@ func TestQueryFonts(t *testing.T) {
 	}
 }
 
+func TestQueryFontMetrics(t *testing.T) {
+	Initialize()
+	defer func(t *testing.T) {
+		checkGC(t)
+	}(t)
+	defer Terminate()
+
+	mw := NewMagickWand()
+	// Create an empty wand. Don't ready anything.
+	//if err := mw.ReadImage("xc:black"); err != nil {
+	//	panic(err)
+	//}
+	fonts := mw.QueryFontMetrics(NewDrawingWand(), "")
+	if fonts != nil {
+		t.Fatal("Expected a nil FontMetrics when passing a bad MagickWand")
+	}
+}
+
 func TestQueryFormats(t *testing.T) {
 	Initialize()
 	defer func(t *testing.T) {