From: Kevin Day <thekevinday@gmail.com>
Date: Wed, 28 Oct 2020 23:14:18 +0000 (-0500)
Subject: Bugfix: trinned string compare functions incorrectly match different strings.
X-Git-Tag: 0.5.1~6
X-Git-Url: https://git.kevux.org/?a=commitdiff_plain;h=06659848437147e3644350f2c1ff49a8fa0313e9;p=fll

Bugfix: trinned string compare functions incorrectly match different strings.

This is happening due to an accidental treatment of the 'last' positions as exclusive stops instead of as inclusive stops.
When they are setup, they are set as the last valid character before whitespace at the end.
Change the logic to make last1 and last2 inclusive stop positions.
---

diff --git a/level_1/fl_string/c/private-string.c b/level_1/fl_string/c/private-string.c
index 325e5e0..387a28a 100644
--- a/level_1/fl_string/c/private-string.c
+++ b/level_1/fl_string/c/private-string.c
@@ -245,14 +245,15 @@ extern "C" {
     f_string_length_t last2 = i2;
 
     {
-      // size1 and size2 are to represent to total number of characters after trim.
+      // size1 and size2 are to represent to total number of characters after trim that are not ignored via "except".
       f_string_length_t size1 = 0;
       f_string_length_t size2 = 0;
 
+      f_string_length_t j = 0;
       f_string_length_t ej = e1;
 
       // determine where the last non-whitespace is in string1.
-      for (f_string_length_t j = i1; j < stop1; j += width) {
+      for (j = i1; j < stop1; j += width) {
 
         // skip past NULL in string1.
         while (j < stop1 && !string1[j]) j++;
@@ -280,14 +281,14 @@ extern "C" {
 
         if (status == F_false) {
           last1 = j;
-          size1++;
+          size1 += width;
         }
       } // for
 
       ej = e2;
 
       // determine where the last non-whitespace is in string2.
-      for (f_string_length_t j = i2; j < stop2; j += width) {
+      for (j = i2; j < stop2; j += width) {
 
         // skip past NULL in string2.
         while (j < stop2 && !string2[j]) j++;
@@ -315,22 +316,22 @@ extern "C" {
 
         if (status == F_false) {
           last2 = j;
-          size2++;
+          size2 += width;
         }
       } // for
 
       if (size1 != size2) return F_equal_to_not;
     }
 
-    while (i1 < last1 && i2 < last2) {
+    while (i1 <= last1 && i2 <= last2) {
 
       // skip past NULL in string1.
-      while (i1 < last1 && !string1[i1]) i1++;
-      if (i1 == last1) break;
+      while (i1 <= last1 && !string1[i1]) i1++;
+      if (i1 > last1) break;
 
       // skip past NULL in string2.
-      while (i2 < last2 && !string2[i2]) i2++;
-      if (i2 == last2) break;
+      while (i2 <= last2 && !string2[i2]) i2++;
+      if (i2 > last2) break;
 
       // skip past except characters in string1.
       while (e1 < except1.used && except1.array[e1] < i1) e1++;
@@ -353,7 +354,7 @@ extern "C" {
     } // while
 
     // only return F_equal_to if all remaining characters are NULL.
-    for (; i1 < last1; i1++) {
+    for (; i1 <= last1; i1++) {
 
       if (string1[i1] != 0) {
 
@@ -365,7 +366,7 @@ extern "C" {
       }
     } // for
 
-    for (; i2 < last2; i2++) {
+    for (; i2 <= last2; i2++) {
 
       if (string2[i2] != 0) {