FIX #1466 (partly), which was causing concprog001(ghci) to fail

[ghc-hetmet.git] / rts / Apply.cmm

diff --git a/rts/Apply.cmm b/rts/Apply.cmm
index c9c7daa..0498f00 100644 (file)
--- a/rts/Apply.cmm
+++ b/rts/Apply.cmm
@@ -249,7 +249,9 @@ INFO_TABLE(stg_AP_STACK,/*special layout*/0,0,AP_STACK,"AP_STACK","AP_STACK")
    * closure, in which case we must enter the blackhole on return rather
    * than continuing to evaluate the now-defunct closure.
    */
-  STK_CHK_NP(WDS(Words) + SIZEOF_StgUpdateFrame);
+  STK_CHK_NP(WDS(Words) + SIZEOF_StgUpdateFrame + WDS(AP_STACK_SPLIM));
+  /* ensure there is at least AP_STACK_SPLIM words of headroom available
+   * after unpacking the AP_STACK. See bug #1466 */
 
   PUSH_UPD_FRAME(Sp - SIZEOF_StgUpdateFrame, R1);
   Sp = Sp - SIZEOF_StgUpdateFrame - WDS(Words);