From 5830f4225cf5e7019b4380e61afad71a9fe629b2 Mon Sep 17 00:00:00 2001
From: Phuntsok Drak-pa <phundrak@phundrak.fr>
Date: Mon, 18 Jun 2018 16:51:06 +0200
Subject: [PATCH] bugfix: fixed writing mask for charsize increase

---
 src/bitpack.cc    | 66 +++++++++++++++++++----------------------------
 src/uncompress.cc |  3 ---
 2 files changed, 27 insertions(+), 42 deletions(-)

diff --git a/src/bitpack.cc b/src/bitpack.cc
index a0a9cd6..8740cda 100644
--- a/src/bitpack.cc
+++ b/src/bitpack.cc
@@ -52,12 +52,6 @@ vuchar pack_n(const vuint16::const_iterator t_input_begin,
   }
   const int max_value = max(t_n); // max value held within t_n bits
 
-#ifdef Debug
-  std::printf("%d bits! %ld chars remaining\n", t_n,
-              std::distance(t_input_begin, t_input_end));
-  std::printf("max: %d\n", max_value);
-#endif
-
   int step = t_n % 8;
   int left_shift = 0;
   int right_shift = 0;
@@ -66,28 +60,30 @@ vuchar pack_n(const vuint16::const_iterator t_input_begin,
 
   // pour chaque élément
   for (auto it = t_input_begin; it != t_input_end; ++it) {
+    // si on a atteint ou dépassé la valeur maximale, on change de nombre de bits
+    if (*it >= max_value) {
+      // écriture du masque pour notifier à la décompression du changement de bits
+      if ((left_shift += step) >= t_n) {
+        left_shift = (left_shift - t_n) + step;
+      }
+      const auto mask = masks[t_n] >> left_shift;
+      t_res.push_back(
+          static_cast<uchar>(current_char | mask));
+      bool zero_rs = (right_shift == 0);
 
-		// si on a atteint ou dépassé la valeur maximale, on change de nombre de bits
-		if (*it >= max_value) {
-			// écriture du masque pour notifier à la décompression du changement de bits
-			if ((left_shift += step) >= t_n) {
-				left_shift = (left_shift - t_n) + step;
-			}
-			const auto mask = masks[t_n] >> left_shift;
-			t_res.push_back(
-					static_cast<uchar>(current_char | mask));
-			bool zero_rs = (right_shift == 0);
-			right_shift -= 0;
-			if(right_shift < 0) {
-				if(!zero_rs) {
-					current_char = static_cast<uchar>(masks[t_n] >> (-right_shift) & 0xffu);
-					t_res.push_back(current_char);
-				}
-			}
-			t_res.push_back(static_cast<uchar>(masks[t_n]));
-			return pack_n(it, t_input_end, t_res, t_n + 1);
-		}
+      right_shift -= step;
+      if(right_shift < 0) { // si right_shift est inférieur à zéro
+        // si right_shift était différent de zéro, alors extra octet
+        if (!zero_rs) {
+          current_char = static_cast<uchar>(masks[t_n] >> (-right_shift) & 0xffu);
+          t_res.push_back(current_char);
+        }
+      }
+      t_res.push_back(static_cast<uchar>(masks[t_n]));
+      return pack_n(it, t_input_end, t_res, t_n + 1);
+    }
 
+    // écriture normale
     if ((left_shift += step) >= t_n) {
       left_shift = (left_shift - t_n) + step;
     }
@@ -122,13 +118,9 @@ vuchar pack_n(const vuint16::const_iterator t_input_begin,
 
 vuchar pack_16(const vuint16::const_iterator t_input_begin,
                const vuint16::const_iterator t_input_end, vuchar t_res) {
-#ifdef Debug
-  std::printf("16 bits! %ld chars remaining\n",
-              std::distance(t_input_begin, t_input_end));
-#endif
   std::for_each(t_input_begin, t_input_end, [&](const auto value) {
-    t_res.push_back((value >> 8) & 0xFFu);
-    t_res.push_back(value & 0xFFu);
+    t_res.push_back(static_cast<uchar>(value >> 8 & 0xFFu));
+    t_res.push_back(static_cast<uchar>(value & 0xFFu));
   });
   return t_res;
 }
@@ -143,10 +135,6 @@ vuint16 unpack(ustring &&t_input) {
 
 vuint16 unpack_n(const ustring::const_iterator t_begin,
                  const ustring::const_iterator t_end, vuint16 t_res, int t_n) {
-#ifdef Debug
-  std::printf("Chunk! %d bits, %ld compressed chars\n", t_n,
-              std::distance(t_begin, t_end));
-#endif
   if (t_n == 16) {
     return unpack_16(t_begin, t_end, vector<uint16_t>());
   }
@@ -157,9 +145,9 @@ vuint16 unpack_n(const ustring::const_iterator t_begin,
   for (auto it = t_begin; it < t_end - 1; /* nope */) {
     uint16_t current_char = 0;
     // left bits
-		if ((left_shift += step) >= t_n) {
-			left_shift = (left_shift - t_n) + step;
-		}
+    if ((left_shift += step) >= t_n) {
+      left_shift = (left_shift - t_n) + step;
+    }
     current_char = static_cast<uint16_t>(*it << left_shift) & masks[t_n];
     // right bits
     bool zero_rs = (right_shift == 0);
diff --git a/src/uncompress.cc b/src/uncompress.cc
index 28ca44f..b1427a2 100644
--- a/src/uncompress.cc
+++ b/src/uncompress.cc
@@ -24,9 +24,6 @@ ustring lzw_uncompress(vuint16 &&t_compressed) {
   for (auto it = t_compressed.begin() + 1; it != t_compressed.end(); ++it) {
     v = *it;
     const auto uncompressed{dico_uncompress(dict, v, old)};
-#ifdef Debug
-    std::printf("%d = %s\n", v, uncompressed.c_str());
-#endif
     ret.insert(ret.end(), uncompressed.begin(), uncompressed.end());
     old = v;
   }