Only set the "WE_HAVE_INSTRUCTIONS" composite flag if a glyph program is actually present
diff --git a/Lib/fontTools/ttLib/tables/_g_l_y_f.py b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
index a6cd1fc..b3edaac 100644
--- a/Lib/fontTools/ttLib/tables/_g_l_y_f.py
+++ b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
@@ -789,7 +789,8 @@
haveInstructions = 0
for i in range(len(self.components)):
if i == lastcomponent:
- haveInstructions = hasattr(self, "program")
+ # Only set haveInstructions if the program is non-zero
+ haveInstructions = hasattr(self, "program") and self.program
more = 0
compo = self.components[i]
data = data + compo.compile(more, haveInstructions, glyfTable)
