Try to avoid fatal filter failures by better scanning during the setup phase.

src/filter/cto.h

@@ -58,8 +58,16 @@ static int F(Filter *f)
         // must not conflict with the mark.
         // Note that unsigned comparison checks both edges of buffer.
         for (ic = 0; ic < size - 5; ic++)
-            if (COND(b,ic) && get_le32(b+ic+1)+ic+1 >= size)
         {
+            if (!COND(b,ic))
+                continue;
+            jc = get_le32(b+ic+1)+ic+1;
+            if (jc < size)
+            {
+                if (jc + addvalue >= (1u << 24)) // hi 8 bits won't be cto8
+                    return -1;
+            }
+            else
                 buf[b[ic+1]] |= 1;
         }
 
@@ -79,8 +87,7 @@ static int F(Filter *f)
         // try to detect 'real' calls only
         if (jc < size)
         {
-            if ((1u<<24)<=(jc+addvalue))  // hi 8 bits won't be cto8
+            assert(jc + addvalue < (1u << 24)); // hi 8 bits won't be cto8
-                return 1;  // fail - buffer not restored
 #ifdef U
             set_be32(b+ic+1,jc+addvalue+cto);
 #endif

src/filter/ctoj.h

@@ -57,8 +57,16 @@ static int F(Filter *f)
         memset(buf,0,256);
 
         for (ic = 0; ic < size - 5; ic++)
-            if (COND(b,ic,lastcall) && get_le32(b+ic+1)+ic+1 >= size)
         {
+            if (!COND(b,ic,lastcall))
+                continue;
+            jc = get_le32(b+ic+1)+ic+1;
+            if (jc < size)
+            {
+                if (jc + addvalue >= (1u << 24)) // hi 8 bits won't be cto8
+                    return -1;
+            }
+            else
                 buf[b[ic+1]] |= 1;
         }
 
@@ -78,8 +86,7 @@ static int F(Filter *f)
         // try to detect 'real' calls only
         if (jc < size)
         {
-            if ((1u<<24)<=(jc+addvalue))  // hi 8 bits won't be cto8
+            assert(jc + addvalue < (1u << 24)); // hi 8 bits won't be cto8
-                return 1;  // fail - buffer not restored
 #ifdef U
             set_be32(b+ic+1,jc+addvalue+cto);
 #endif

src/filter/ctok.h

@@ -58,8 +58,16 @@ static int F(Filter *f)
         memset(buf,0,256);
 
         for (ic = 0; ic < size - 5; ic++)
-            if (COND(b,ic,lastcall,id) && get_le32(b+ic+1)+ic+1 >= size)
         {
+            if (!COND(b,ic,lastcall,id))
+                continue;
+            jc = get_le32(b+ic+1)+ic+1;
+            if (jc < size)
+            {
+                if (jc + addvalue >= (1u << 24)) // hi 8 bits won't be cto8
+                    return -1;
+            }
+            else
                 buf[b[ic+1]] |= 1;
         }
 
@@ -79,8 +87,7 @@ static int F(Filter *f)
         // try to detect 'real' calls only
         if (jc < size)
         {
-            if ((1u<<24)<=(jc+addvalue))  // hi 8 bits won't be cto8
+            assert(jc + addvalue < (1u << 24)); // hi 8 bits won't be cto8
-                return 1;  // fail - buffer not restored
 #ifdef U
             set_be32(b+ic+1,jc+addvalue+cto);
 #endif