Clarify crc32 variable names (#2367)

No functional change, just a tiny style improvement.

Use `crc32_computed` to refer to the crc32 that the reader has computed
and `crc32_read` to refer to the value that we read from the archive.
That hopefully makes this code a tiny bit easier to follow. (It confused
me recently when I was double-checking something in this area, so I
thought an improvement here might help others.)

diff --git a/libarchive/archive_read_support_format_rar.c b/libarchive/archive_read_support_format_rar.c
index af2831b361e46c3958bc62d20d51d1cb4ab9e2be..9cf4d639a79db2802345a1b3c09e3dbf10d73dd4 100644 (file)
--- a/libarchive/archive_read_support_format_rar.c
+++ b/libarchive/archive_read_support_format_rar.c
@@ -1371,7 +1371,7 @@ read_header(struct archive_read *a, struct archive_entry *entry,
   char unp_size[8];
   int ttime;
   struct archive_string_conv *sconv, *fn_sconv;
-  unsigned long crc32_val;
+  uint32_t crc32_computed, crc32_read;
   int ret = (ARCHIVE_OK), ret2;
   char *newptr;
   size_t newsize;
@@ -1402,7 +1402,7 @@ read_header(struct archive_read *a, struct archive_entry *entry,
       "Invalid header size");
     return (ARCHIVE_FATAL);
   }
-  crc32_val = crc32(0, (const unsigned char *)p + 2, 7 - 2);
+  crc32_computed = crc32(0, (const unsigned char *)p + 2, 7 - 2);
   __archive_read_consume(a, 7);
 
   if (!(rar->file_flags & FHD_SOLID))
@@ -1436,8 +1436,9 @@ read_header(struct archive_read *a, struct archive_entry *entry,
     return (ARCHIVE_FATAL);
 
   /* File Header CRC check. */
-  crc32_val = crc32(crc32_val, h, (unsigned)(header_size - 7));
-  if ((crc32_val & 0xffff) != archive_le16dec(rar_header.crc)) {
+  crc32_computed = crc32(crc32_computed, h, (unsigned)(header_size - 7));
+  crc32_read = archive_le16dec(rar_header.crc);
+  if ((crc32_computed & 0xffff) != crc32_read) {
 #ifndef DONT_FAIL_ON_CRC_ERROR
     archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
       "Header CRC error");