Tries module: when loading a trie from a file, we now check if the file is corrupted before starting loading.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@2232 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

library/Tries/base_itries.c

@@ -369,12 +369,15 @@ TrEntry itrie_load(FILE *file) {
   TrNode node;
 
   new_itrie_entry(itrie, NULL);
+  CURRENT_ITRIE = itrie;
+  if (!(node = core_trie_load(ITRIE_ENGINE, file, &itrie_data_load))) {
+    free_itrie_entry(itrie);
+    return NULL;
+  }
+  TrEntry_trie(itrie) = node;
   if (FIRST_ITRIE)
     TrEntry_previous(FIRST_ITRIE) = itrie;
   FIRST_ITRIE = itrie;
-  CURRENT_ITRIE = itrie;
-  node = core_trie_load(ITRIE_ENGINE, file, &itrie_data_load);
-  TrEntry_trie(itrie) = node;
   return itrie;
 }
 

library/Tries/base_tries.c

@@ -240,12 +240,15 @@ TrEntry trie_load(FILE *file) {
   TrNode node;
 
   new_trie_entry(trie, NULL);
+  CURRENT_TRIE = trie;
+  if (!(node = core_trie_load(TRIE_ENGINE, file, &trie_data_load))) {
+    free_trie_entry(trie);  
+    return NULL;
+  }
+  TrEntry_trie(trie) = node;
   if (FIRST_TRIE)
     TrEntry_previous(FIRST_TRIE) = trie;
   FIRST_TRIE = trie;
-  CURRENT_TRIE = trie;
-  node = core_trie_load(TRIE_ENGINE, file, &trie_data_load);
-  TrEntry_trie(trie) = node;
   return trie;
 }
 

library/Tries/core_tries.c

@@ -429,19 +429,41 @@ TrNode core_trie_load(TrEngine engine, FILE *file, void (*load_function)(TrNode,
   TrNode node;
   char version[15];
 
+  fscanf(file, "%14s", version);
+  if (!strcmp(version, "BEGIN_TRIE_v2")) {
+    fseek(file, -11, SEEK_END);
+    fscanf(file, "%s", version);
+    if (strcmp(version, "END_TRIE_v2")) {
+      fprintf(stderr, "******************************************\n");
+      fprintf(stderr, "  Tries core module: trie file corrupted\n");
+      fprintf(stderr, "******************************************\n");  
+      return NULL;
+    }
+    fseek(file, 13, SEEK_SET);
+    CURRENT_LOAD_VERSION = 2;
+  } else if (!strcmp(version, "BEGIN_TRIE")) {
+    fseek(file, -8, SEEK_END);
+    fscanf(file, "%s", version);
+    if (strcmp(version, "END_TRIE")) {
+      fprintf(stderr, "******************************************\n");
+      fprintf(stderr, "  Tries core module: trie file corrupted\n");
+      fprintf(stderr, "******************************************\n");  
+      return NULL;
+    }
+    fseek(file, 10, SEEK_SET);
+    CURRENT_LOAD_VERSION = 1;
+  } else {
+    fprintf(stderr, "****************************************\n");
+    fprintf(stderr, "  Tries core module: invalid trie file\n");
+    fprintf(stderr, "****************************************\n");  
+    return NULL;
+  }
   CURRENT_TRIE_ENGINE = engine;
   CURRENT_INDEX = -1;
   CURRENT_DEPTH = 0;
   DATA_LOAD_FUNCTION = load_function;
   node = core_trie_open(engine);
-  fscanf(file, "%s", version);
-  if (!strcmp(version, "BEGIN_TRIE_v2")) {
-    CURRENT_LOAD_VERSION = 2;
-    traverse_and_load(node, file);
-  } else if (!strcmp(version, "BEGIN_TRIE")) {
-    CURRENT_LOAD_VERSION = 1;
-    traverse_and_load(node, file);
-  }
+  traverse_and_load(node, file);
   return node;
 }
 

library/Tries/itries.c

@@ -579,6 +579,8 @@ static int p_itrie_load(void) {
   itrie = itrie_load(file);
   if (fclose(file))
     return FALSE;
+  if (!itrie)
+    return FALSE;
   return YAP_Unify(arg_itrie, YAP_MkIntTerm((YAP_Int) itrie));
 }
 #undef arg_itrie

library/Tries/tries.c

@@ -527,6 +527,8 @@ static int p_trie_load(void) {
   data = trie_load(file);
   if (fclose(file))
     return FALSE;
+  if (!data)
+    return FALSE;
   return YAP_Unify(arg_trie, YAP_MkIntTerm((YAP_Int) data));
 }
 #undef arg_trie