svn commit: r328462 - stable/11/usr.bin/patch

[Kyle Evans]

Author: kevans
Date: Sat Jan 27 06:20:27 2018
New Revision: 328462
URL: https://svnweb.freebsd.org/changeset/base/328462

Log:
  MFC r327826: patch(1): Don't check for NUL bytes in Plan A
  
  Plan A mmap()'s the entire input file and operates on it in memory. The
  map(2) call succeeded, so we shouldn't need to bother checking for the NUL
  byte as long as we're within our buffer space.
  
  This was clearly intentional to match "the behavior of the original code",
  but it creates a discrepancy between Plan A and Plan B that doesn't seem
  sensible and it's not inherently wrong to allow a NUL byte.
  
  This change was motivated by the gemspec in net/rubygem-grpc failing to
  patch, despite the patch being generated with diff, because a NUL byte was
  used as a delimiter in the header briefly in an otherwise text file.
  
  An alternative was considered: to fallback to plan B if plan A won't process
  the entire file due to a NUL byte, but I deemed this to be the better option
  since plan A isn't failing due to memory limitations and will fail later on
  if it's really dealing with a file it shouldn't be.

Modified:
  stable/11/usr.bin/patch/inp.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/usr.bin/patch/inp.c
==============================================================================
--- stable/11/usr.bin/patch/inp.c	Sat Jan 27 06:15:24 2018	(r328461)
+++ stable/11/usr.bin/patch/inp.c	Sat Jan 27 06:20:27 2018	(r328462)
@@ -213,8 +213,11 @@ plan_a(const char *filename)
 	/* now scan the buffer and build pointer array */
 	iline = 1;
 	i_ptr[iline] = i_womp;
-	/* test for NUL too, to maintain the behavior of the original code */
-	for (s = i_womp, i = 0; i < i_size && *s != '\0'; s++, i++) {
+	/*
+	 * Testing for NUL here actively breaks files that innocently use NUL
+	 * for other reasons. mmap(2) succeeded, just scan the whole buffer.
+	 */
+	for (s = i_womp, i = 0; i < i_size; s++, i++) {
 		if (*s == '\n') {
 			if (iline == lines_allocated) {
 				if (!reallocate_lines(&lines_allocated))