X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdata%2Fcase.h;h=05c4568c6befe3f501cfcf65dd622ab10ee6023c;hb=2153ca9b3cb9616c616a4b58abb300de1f317541;hp=bdb68dc65b55617a463fe0ca6ab10a9892d9327b;hpb=a19b858e0ac3c69e4a28c0ca6d8674427268a863;p=pspp

diff --git a/src/data/case.h b/src/data/case.h
index bdb68dc65b..05c4568c6b 100644
--- a/src/data/case.h
+++ b/src/data/case.h
@@ -115,8 +115,11 @@ case_clone (struct ccase *clone, const struct ccase *orig)
 static inline void
 case_move (struct ccase *dst, struct ccase *src) 
 {
-  *dst = *src;
-  src->case_data = NULL;
+  if (dst != src) 
+    {
+      *dst = *src;
+      src->case_data = NULL; 
+    }
 }
 
 static inline void
@@ -132,12 +135,14 @@ case_copy (struct ccase *dst, size_t dst_idx,
            const struct ccase *src, size_t src_idx,
            size_t value_cnt) 
 {
-  if (dst->case_data->ref_cnt > 1)
-    case_unshare (dst);
   if (dst->case_data != src->case_data || dst_idx != src_idx) 
-    memmove (dst->case_data->values + dst_idx,
-             src->case_data->values + src_idx,
-             sizeof *dst->case_data->values * value_cnt); 
+    {
+      if (dst->case_data->ref_cnt > 1)
+        case_unshare (dst);
+      memmove (dst->case_data->values + dst_idx,
+               src->case_data->values + src_idx,
+               sizeof *dst->case_data->values * value_cnt); 
+    }
 }
 
 static inline void