Change string_to_symbol to compute the correct argument to

Primitive_GC.  Previously it was using (Memtop - Free) which could
have been negative (and we saw at least one case where something like
that had happened).

diff --git a/v7/src/microcode/utils.c b/v7/src/microcode/utils.c
index 14c74571ac82a8443e8295ffbb4d0f53da6a69ef..67db4380ff501570d51372cb324a78278f023917 100644 (file)
--- a/v7/src/microcode/utils.c
+++ b/v7/src/microcode/utils.c
@@ -30,7 +30,7 @@ Technology nor of any adaptation thereof in any advertising,
 promotional, or sales literature without prior written consent from
 MIT in each case. */
 
-/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/utils.c,v 9.23 1987/04/16 02:32:25 jinx Exp $ */
+/* $Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/utils.c,v 9.24 1987/04/21 15:22:08 cph Exp $ */
 
 /* This file contains utilities for interrupts, errors, etc. */
 
@@ -662,14 +662,26 @@ C_String_To_Scheme_String (C_String)
   Max_Length = ((Space_Before_GC() - STRING_CHARS) *
                 sizeof( Pointer));
   if (C_String == NULL)
-    Length = 0;
+    {
+      Length = 0;
+      if (Max_Length < 0)
+       Primitive_GC(3);
+    }
   else
-    for (Length = 0;
-        (*C_String != '\0') && (Length < Max_Length);
-        Length += 1)
-      *Next++ = *C_String++;
-  if (Length >= Max_Length)
-    Primitive_GC( MemTop - Free);
+    {
+      for (Length = 0;
+          (*C_String != '\0') && (Length < Max_Length);
+          Length += 1)
+       *Next++ = *C_String++;
+      if (Length >= Max_Length)
+       {
+         while (*C_String++ != '\0')
+           Length += 1;
+         Primitive_GC(2 +
+                      (((Length + 1) + (sizeof( Pointer) - 1))
+                       / sizeof( Pointer)));
+       }
+    }
   *Next = '\0';
   Free += (2 + ((Length + sizeof( Pointer)) / sizeof( Pointer)));
   Vector_Set(Result, STRING_LENGTH, Length);