Internal selftest added. Keyboard-layout integrity checked.

Test binaries perform additional selftests now.
This helps to detect errors in keyboard layout definitions early.

test.c

@@ -33,6 +33,9 @@
 #include "stdafx.h"
 #endif
 
+/* forward declaration / not part of official API */
+unsigned int _selftest_errors();
+
 const char *UsrDict[] =
 {
     "Onename.Twoname@example.com", "Onename", "Twoname", "example.com", "example",
@@ -207,9 +210,16 @@ int DoChecks(char *file)
 int main(int argc, char **argv)
 {
     int i, Quiet, Checks, White;
+    unsigned int SelftestErrors;
     Quiet = 0;
     Checks = 0;
     White = 0;
+
+    SelftestErrors = _selftest_errors();
+    printf("Selftest returned %d error(s).\n", SelftestErrors );
+    if (SelftestErrors)
+      return 1;
+
     if (!ZxcvbnInit("zxcvbn.dict"))
     {
         printf("Failed to open dictionary file\n");

zxcvbn.c

@@ -29,6 +29,13 @@
 #include <math.h>
 #include <float.h>
 
+/* printf */
+#ifdef __cplusplus
+#include <cstdio>
+#else
+#include <stdio.h>
+#endif
+
 #ifdef USE_DICT_FILE
 #if defined(USE_FILE_IO) || !defined(__cplusplus)
 #include <stdio.h>
@@ -932,7 +939,7 @@ typedef struct
 static const uint8_t US_Shift[] = "!1\"'#3$4%5&7(9)0*8:;<,>.?/@2AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz^6_-{[|\\}]~`";
 
 
-/* Neighour tables */
+/* Neighbour tables */
 static const uint8_t UK_Qwerty[48*7] =
 {
 /* key, left, up-left, up-right, right, down-right, down-left */
@@ -1759,3 +1766,137 @@ void ZxcvbnFreeInfo(ZxcMatch_t *Info)
         Info = p;
     }
 }
+
+/**********************************************************************************
+ * Internal checks: Validate if the first element of each group is sorted in
+ *                  ascending order. CharBinSearch(...) fails otherwise.
+ * Returns 0 on success.
+ * Returns element index [1..] of first error entry that is less than previous one.
+ */
+static int _check_order(const uint8_t *Ents, unsigned int NumEnts, unsigned int SizeEnts) {
+  const uint8_t *last;
+  unsigned int i;
+
+  if (!Ents) return 0;
+  last = 0;
+
+  for (i = 0; i < NumEnts; ++i, Ents += SizeEnts) {
+    if (last  &&  *last > *Ents) {
+      unsigned int j;
+
+      printf("Entry#%d [%d]:  '%c' > '%c'  (0x%02X > 0x%02X)\n    A:  ", i, i * SizeEnts, *last, *Ents, *last, *Ents);
+      for (j = 0; j < SizeEnts; ++j) {
+        printf("'%c' ", last[j] ? last[j] : ' ');
+      }
+      printf("\n    >\n    B:  ");
+      for (j = 0; j < SizeEnts; ++j) {
+        printf("'%c' ", Ents[j] ? Ents[j] : ' ');
+      }
+      printf("\n");
+
+      return i;
+    }
+    last = Ents;
+  }
+
+  return 0; /* cannot be a misordered position; first possible one: 1 */
+}
+
+/**********************************************************************************
+ * Internal checks: Checks keyboard data integrity.
+ * Returns 0 on succes.
+ * Otherwise, number of errors are reported.
+ */
+static unsigned int _selftest_keyboards() {
+  unsigned int errors;
+  const Keyboard_t *k;
+  unsigned int Indx;
+  const uint8_t *keys;
+  int i,j,errpos, blanks;
+
+  errors = 0;
+  for(k = Keyboards, Indx = 0; Indx < (sizeof Keyboards / sizeof Keyboards[0]); ++Indx, ++k) {
+    /* if one of these assrtion fails, we cannot use binary search algorithm */
+    if (k->Shifts  &&  strlen((const char*)k->Shifts) % 2 == 1) {
+      printf("ERROR: Keyboard[%d]: Shifts-string has odd number of entries.\n", Indx);
+      ++errors;
+    }
+
+    if ( (errpos = _check_order(k->Shifts, k->NumShift, 2)) ) {
+      printf("ERROR: Keyboard[%d]: Error above in sort order of Shifts-string near item #%d.\n", Indx, errpos);
+      ++errors;
+    }
+
+    if ( (errpos = _check_order(k->Keys, k->NumKeys, k->NumNear)) ) {
+      printf("ERROR: Keyboard[%d]: Error above in sort order of keyboard-entries! Problem near item #%d.\n", Indx, errpos);
+      ++errors;
+      continue;
+    }
+
+    /* For each key (c0), check all its neighbours (ci):
+     * Does the neighbour key (c1==ci) have an entry (cx) in the opposite direction [rev_idx]
+     * pointing back to the current key c0?
+     * c0: ...ci..   -->   c1: ..cx...   -->   cx==c0?
+     */
+    keys = k->Keys;
+    blanks = 0;
+    for(i = 0; i < k->NumKeys; ++i) {
+      uint8_t c0;
+      c0 = keys[i * k->NumNear];
+
+      for (j = 0; j < k->NumNear - 1; ++j) {
+        const uint8_t *c1;
+        uint8_t ci, cx;
+        int rev_idx;
+
+        /* rev_idx: reverse/opposite index to find opposite key location [0..6|8] --> [0..6|8] */
+        rev_idx = (j + (k->NumNear - 1)/2) % (k->NumNear - 1);
+        ci = keys[i * k->NumNear + j + 1];
+
+        if (ci) {
+          c1 = CharBinSearch(ci, keys, k->NumKeys, k->NumNear);
+          if (c1) {
+            if (ci == c0) {
+              printf("ERROR: Keyboard[%d]:  recursion - key '%c' cannot be its own neighbour!\n", Indx, *c1);
+              ++errors;
+            } else {
+              if ( (cx = c1[ 1 + rev_idx ]) ) {
+                if ( cx != c0 ) {
+                  printf("ERROR: Keyboard[%d]:  c0='%c':...(ci=%c)... ->  c1='%c':...(cx=%c)... --!--> c0='%c':... \n",
+                         Indx, c0, ci, *c1, cx, c0);
+                  ++errors;
+                }
+              } else { /* reverse pointer is NULL */
+                printf("ERROR: Keyboard[%d]:  reverse entry missing in row c1='%c'[%d] pointing back to c0='%c'!\n", Indx, *c1, 1+rev_idx, c0);
+                ++errors;
+              }
+            }
+          } else {
+            printf("ERROR: Keyboard[%d]:  no entry (neighbour list) found for src-char c1==ci='%c'\n", Indx, ci);
+            ++errors;
+          }
+        } else { /* blank neighbour key reference found */
+          ++blanks;
+        }
+      }
+    }
+    if (blanks != k->NumBlank) {
+      printf("ERROR: Keyboard[%d]:  number of blank keys announced (%d) does not match number of blank keys counted (%d)!\n",
+             Indx, k->NumBlank, blanks);
+      ++errors;
+    }
+  }
+  return errors;
+}
+
+/**********************************************************************************
+ * Performs all internal checks.
+ * Should be used by test programs.  Might be used by applications.
+ * Returns 0 on success (no output).
+ * Reports number of errors otherwise. Error indication printed to STDOUT.
+ */
+unsigned int _selftest_errors() {
+  unsigned int errors;
+  errors = _selftest_keyboards();  /* currently only these */
+  return errors;
+}