Update filter histories even when they're not used

If the filter properties are continually updated, and the HF or LF gain goes
from <1, to 1, and later back to <1, the history shouldn't hold stale values
from before it was at 1.

1 files changed, 4 insertions, 0 deletions

diff --git a/Alc/mixer.c b/Alc/mixer.c
index e8b94b17..4917477a 100644
--- a/Alc/mixer.c
+++ b/Alc/mixer.c
@@ -260,12 +260,16 @@ static const ALfloat *DoFilters(ALfilterState *lpfilter, ALfilterState *hpfilter
     switch(type)
     {
         case AF_None:
+            ALfilterState_processPassthru(lpfilter, src, numsamples);
+            ALfilterState_processPassthru(hpfilter, src, numsamples);
             break;
 
         case AF_LowPass:
             ALfilterState_process(lpfilter, dst, src, numsamples);
+            ALfilterState_processPassthru(hpfilter, dst, numsamples);
             return dst;
         case AF_HighPass:
+            ALfilterState_processPassthru(lpfilter, src, numsamples);
             ALfilterState_process(hpfilter, dst, src, numsamples);
             return dst;