Fix an abstraction violation.

Don't alias the insides of smartlist_t; that way lies madness.

diff --git a/src/or/consdiff.c b/src/or/consdiff.c
index 2b1439569c70a0bdfad5de5afad84984ab30d481..6fe8360902399b7ca80d41d7707b9b64e4f6fb42 100644 (file)
--- a/src/or/consdiff.c
+++ b/src/or/consdiff.c
@@ -654,18 +654,19 @@ gen_ed_diff(const smartlist_t *cons1, const smartlist_t *cons2)
   return NULL;
 }
 
-/** Apply the ed diff to the consensus and return a new consensus, also as a
- * line-based smartlist. Will return NULL if the ed diff is not properly
- * formatted.
+/** Apply the ed diff, starting at <b>diff_starting_line</b>, to the consensus
+ * and return a new consensus, also as a line-based smartlist. Will return
+ * NULL if the ed diff is not properly formatted.
  */
 STATIC smartlist_t *
-apply_ed_diff(const smartlist_t *cons1, const smartlist_t *diff)
+apply_ed_diff(const smartlist_t *cons1, const smartlist_t *diff,
+              int diff_starting_line)
 {
   int diff_len = smartlist_len(diff);
   int j = smartlist_len(cons1);
   smartlist_t *cons2 = smartlist_new();
 
-  for (int i=0; i<diff_len; ++i) {
+  for (int i=diff_starting_line; i<diff_len; ++i) {
     const char *diff_line = smartlist_get(diff, i);
     char *endptr1, *endptr2;
 
@@ -811,7 +812,7 @@ consdiff_gen_diff(const smartlist_t *cons1, const smartlist_t *cons2,
   }
 
   /* See that the script actually produces what we want. */
-  smartlist_t *ed_cons2 = apply_ed_diff(cons1, ed_diff);
+  smartlist_t *ed_cons2 = apply_ed_diff(cons1, ed_diff, 0);
   if (!ed_cons2) {
     /* LCOV_EXCL_START -- impossible if diff generation is correct */
     log_warn(LD_BUG|LD_CONSDIFF, "Refusing to generate consensus diff because "
@@ -978,16 +979,8 @@ consdiff_apply_diff(const smartlist_t *cons1,
   }
 
   /* Grab the ed diff and calculate the resulting consensus. */
-  /* To avoid copying memory or iterating over all the elements, make a
-   * read-only smartlist without the two header lines.
-   */
-  /* XXXX prop140 abstraction violation; never do this. */
-  smartlist_t *ed_diff = tor_malloc(sizeof(smartlist_t));
-  ed_diff->list = diff->list+2;
-  ed_diff->num_used = diff->num_used-2;
-  ed_diff->capacity = diff->capacity-2;
-  cons2 = apply_ed_diff(cons1, ed_diff);
-  tor_free(ed_diff);
+  /* Skip the first two lines. */
+  cons2 = apply_ed_diff(cons1, diff, 2);
 
   /* ed diff could not be applied - reason already logged by apply_ed_diff. */
   if (!cons2) {

diff --git a/src/or/consdiff.h b/src/or/consdiff.h
index 3316ed6879dfc70909385f07ccdcc53a80f58c68..42cd3afa8361681d54367d3a6da15c1b2224354a 100644 (file)
--- a/src/or/consdiff.h
+++ b/src/or/consdiff.h
@@ -37,7 +37,8 @@ typedef struct smartlist_slice_t {
 STATIC smartlist_t *gen_ed_diff(const smartlist_t *cons1,
                                 const smartlist_t *cons2);
 STATIC smartlist_t *apply_ed_diff(const smartlist_t *cons1,
-                                  const smartlist_t *diff);
+                                  const smartlist_t *diff,
+                                  int start_line);
 STATIC void calc_changes(smartlist_slice_t *slice1, smartlist_slice_t *slice2,
                          bitarray_t *changed1, bitarray_t *changed2);
 STATIC smartlist_slice_t *smartlist_slice(const smartlist_t *list,

diff --git a/src/test/test_consdiff.c b/src/test/test_consdiff.c
index 2afebfe2ab3e8689ae89a06ec71b2d7964c1c739..12213aab6405ddd85a25b970efc881cd76f33f00 100644 (file)
--- a/src/test/test_consdiff.c
+++ b/src/test/test_consdiff.c
@@ -632,7 +632,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   /* Command without range. */
   smartlist_add(diff, (char*)"a");
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   smartlist_clear(diff);
   expect_single_log_msg_containing("an ed command was missing a line number");
@@ -640,7 +640,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Range without command. */
   smartlist_add(diff, (char*)"1");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("a line with no ed command was found");
 
@@ -649,7 +649,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Range without end. */
   smartlist_add(diff, (char*)"1,");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("an ed command was missing a range "
                                    "end line number.");
@@ -659,7 +659,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Incoherent ranges. */
   smartlist_add(diff, (char*)"1,1");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("an invalid range was found");
 
@@ -667,7 +667,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   smartlist_add(diff, (char*)"3,2");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("an invalid range was found");
 
@@ -677,7 +677,7 @@ test_consdiff_apply_ed_diff(void *arg)
   smartlist_add(diff, (char*)"1d");
   smartlist_add(diff, (char*)"3d");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("its commands are not properly sorted");
 
@@ -686,7 +686,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Script contains unrecognised commands longer than one char. */
   smartlist_add(diff, (char*)"1foo");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("an ed command longer than one char was "
                                    "found");
@@ -696,7 +696,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Script contains unrecognised commands. */
   smartlist_add(diff, (char*)"1e");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("an unrecognised ed command was found");
 
@@ -706,7 +706,7 @@ test_consdiff_apply_ed_diff(void *arg)
    * isn't. */
   smartlist_add(diff, (char*)"0a");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("it has an ed command that tries to "
                                    "insert zero lines.");
@@ -714,7 +714,7 @@ test_consdiff_apply_ed_diff(void *arg)
   /* Now it is followed by a ".", but it inserts zero lines. */
   smartlist_add(diff, (char*)".");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("it has an ed command that tries to "
                                    "insert zero lines.");
@@ -725,7 +725,7 @@ test_consdiff_apply_ed_diff(void *arg)
   smartlist_add(diff, (char*)"0a");
   smartlist_add(diff, (char*)"hello");
   mock_clean_saved_logs();
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_EQ, cons2);
   expect_single_log_msg_containing("lines to be inserted that don't end with "
                                    "a \".\".");
@@ -734,7 +734,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   /* Test appending text, 'a'. */
   smartlist_split_string(diff, "3a:U:O:.:0a:V:.", ":", 0, 0);
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_NE, cons2);
   tt_int_op(8, OP_EQ, smartlist_len(cons2));
   tt_str_op("V", OP_EQ, smartlist_get(cons2, 0));
@@ -753,7 +753,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   /* Test deleting text, 'd'. */
   smartlist_split_string(diff, "4d:1,2d", ":", 0, 0);
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_NE, cons2);
   tt_int_op(2, OP_EQ, smartlist_len(cons2));
   tt_str_op("C", OP_EQ, smartlist_get(cons2, 0));
@@ -766,7 +766,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   /* Test changing text, 'c'. */
   smartlist_split_string(diff, "4c:T:X:.:1, 2c:M:.", ":", 0, 0);
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_NE, cons2);
   tt_int_op(5, OP_EQ, smartlist_len(cons2));
   tt_str_op("M", OP_EQ, smartlist_get(cons2, 0));
@@ -782,7 +782,7 @@ test_consdiff_apply_ed_diff(void *arg)
 
   /* Test 'a', 'd' and 'c' together. */
   smartlist_split_string(diff, "4c:T:X:.:2d:0a:M:.", ":", 0, 0);
-  cons2 = apply_ed_diff(cons1, diff);
+  cons2 = apply_ed_diff(cons1, diff, 0);
   tt_ptr_op(NULL, OP_NE, cons2);
   tt_int_op(6, OP_EQ, smartlist_len(cons2));
   tt_str_op("M", OP_EQ, smartlist_get(cons2, 0));