From 8678871f18f4dd51101a9db1e37791f975969079 Mon Sep 17 00:00:00 2001
From: Mark Adler <madler@alumni.caltech.edu>
Date: Fri, 31 Dec 2021 16:57:07 -0800
Subject: [PATCH] Replace black/white with allow/block. (theresa-m)

---
 doc/txtvsbin.txt | 12 ++++++------
 trees.c          | 18 +++++++++---------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/doc/txtvsbin.txt b/doc/txtvsbin.txt
index 3d0f063..2a901ea 100644
--- a/doc/txtvsbin.txt
+++ b/doc/txtvsbin.txt
@@ -38,15 +38,15 @@ The Algorithm
 
 The algorithm works by dividing the set of bytecodes [0..255] into three
 categories:
-- The white list of textual bytecodes:
+- The allow list of textual bytecodes:
   9 (TAB), 10 (LF), 13 (CR), 32 (SPACE) to 255.
 - The gray list of tolerated bytecodes:
   7 (BEL), 8 (BS), 11 (VT), 12 (FF), 26 (SUB), 27 (ESC).
-- The black list of undesired, non-textual bytecodes:
+- The block list of undesired, non-textual bytecodes:
   0 (NUL) to 6, 14 to 31.
 
-If a file contains at least one byte that belongs to the white list and
-no byte that belongs to the black list, then the file is categorized as
+If a file contains at least one byte that belongs to the allow list and
+no byte that belongs to the block list, then the file is categorized as
 plain text; otherwise, it is categorized as binary.  (The boundary case,
 when the file is empty, automatically falls into the latter category.)
 
@@ -84,9 +84,9 @@ consistent results, regardless what alphabet encoding is being used.
 results on a text encoded, say, using ISO-8859-16 versus UTF-8.)
 
 There is an extra category of plain text files that are "polluted" with
-one or more black-listed codes, either by mistake or by peculiar design
+one or more block-listed codes, either by mistake or by peculiar design
 considerations.  In such cases, a scheme that tolerates a small fraction
-of black-listed codes would provide an increased recall (i.e. more true
+of block-listed codes would provide an increased recall (i.e. more true
 positives).  This, however, incurs a reduced precision overall, since
 false positives are more likely to appear in binary files that contain
 large chunks of textual data.  Furthermore, "polluted" plain text should
diff --git a/trees.c b/trees.c
index decaeb7..6896067 100644
--- a/trees.c
+++ b/trees.c
@@ -1091,9 +1091,9 @@ local void compress_block(s, ltree, dtree)
  * Check if the data type is TEXT or BINARY, using the following algorithm:
  * - TEXT if the two conditions below are satisfied:
  *    a) There are no non-portable control characters belonging to the
- *       "black list" (0..6, 14..25, 28..31).
+ *       "block list" (0..6, 14..25, 28..31).
  *    b) There is at least one printable character belonging to the
- *       "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
+ *       "allow list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
  * - BINARY otherwise.
  * - The following partially-portable control characters form a
  *   "gray list" that is ignored in this detection algorithm:
@@ -1103,19 +1103,19 @@ local void compress_block(s, ltree, dtree)
 local int detect_data_type(s)
     deflate_state *s;
 {
-    /* black_mask is the bit mask of black-listed bytes
+    /* block_mask is the bit mask of block-listed bytes
      * set bits 0..6, 14..25, and 28..31
      * 0xf3ffc07f = binary 11110011111111111100000001111111
      */
-    unsigned long black_mask = 0xf3ffc07fUL;
+    unsigned long block_mask = 0xf3ffc07fUL;
     int n;
 
-    /* Check for non-textual ("black-listed") bytes. */
-    for (n = 0; n <= 31; n++, black_mask >>= 1)
-        if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
+    /* Check for non-textual ("block-listed") bytes. */
+    for (n = 0; n <= 31; n++, block_mask >>= 1)
+        if ((block_mask & 1) && (s->dyn_ltree[n].Freq != 0))
             return Z_BINARY;
 
-    /* Check for textual ("white-listed") bytes. */
+    /* Check for textual ("allow-listed") bytes. */
     if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0
             || s->dyn_ltree[13].Freq != 0)
         return Z_TEXT;
@@ -1123,7 +1123,7 @@ local int detect_data_type(s)
         if (s->dyn_ltree[n].Freq != 0)
             return Z_TEXT;
 
-    /* There are no "black-listed" or "white-listed" bytes:
+    /* There are no "block-listed" or "allow-listed" bytes:
      * this stream either is empty or has tolerated ("gray-listed") bytes only.
      */
     return Z_BINARY;