(gc_sweep): Prevent symbols read during loadup

from being freed.

1 files changed, 24 insertions, 17 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 23ab3a3bcd2..83007657e20 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -4764,29 +4764,36 @@ gc_sweep ()
     register int lim = symbol_block_index;
     register int num_free = 0, num_used = 0;
 
-    symbol_free_list = 0;
+    symbol_free_list = NULL;
   
     for (sblk = symbol_block; sblk; sblk = *sprev)
       {
-        register int i;
         int this_free = 0;
-        for (i = 0; i < lim; i++)
-          if (!XMARKBIT (sblk->symbols[i].plist))
-            {
-              *(struct Lisp_Symbol **)&sblk->symbols[i].value = symbol_free_list;
-              symbol_free_list = &sblk->symbols[i];
+        struct Lisp_Symbol *sym = sblk->symbols;
+        struct Lisp_Symbol *end = sym + lim;
+
+        for (; sym < end; ++sym)
+          {
+            int pure_p = PURE_POINTER_P (sym->name);
+            
+            if (!XMARKBIT (sym->plist) && !pure_p)
+              {
+                *(struct Lisp_Symbol **) &sym->value = symbol_free_list;
+                symbol_free_list = sym;
 #if GC_MARK_STACK
-              symbol_free_list->function = Vdead;
+                symbol_free_list->function = Vdead;
 #endif
-              this_free++;
-            }
-          else
-            {
-              num_used++;
-              if (!PURE_POINTER_P (sblk->symbols[i].name))
-                UNMARK_STRING (sblk->symbols[i].name);
-              XUNMARK (sblk->symbols[i].plist);
-            }
+                ++this_free;
+              }
+            else
+              {
+                ++num_used;
+                if (!pure_p)
+                  UNMARK_STRING (sym->name);
+                XUNMARK (sym->plist);
+              }
+          }
+        
         lim = SYMBOL_BLOCK_SIZE;
         /* If this block contains only free symbols and we have already
            seen more than two blocks worth of free symbols then deallocate