apply: replace NO_ACCURATE_DIFF with --inaccurate-eof runtime flag.

It does not make much sense to build git whose behaviour is
different depending on the brokenness of diff implementation of
the platform because the brokenness of the patch that is applied
with the tool depends on brokenness of the diff the person who
generates the patch uses.  So we do not use NO_ACCURATE_DIFF
anymore, but help people to apply patches that do not record
incomplete lines correctly with a runtime flag.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

builtin-apply.c

@@ -125,6 +125,7 @@ struct patch {
 	unsigned long deflate_origlen;
 	int lines_added, lines_deleted;
 	int score;
+	int inaccurate_eof:1;
 	struct fragment *fragments;
 	char *result;
 	unsigned long resultsize;
@@ -1333,7 +1334,8 @@ static int apply_line(char *output, const char *patch, int plen)
 	return plen;
 }
 
-static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
+static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag,
+	int inaccurate_eof)
 {
 	int match_beginning, match_end;
 	char *buf = desc->buffer;
@@ -1386,13 +1388,11 @@ static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
 		size -= len;
 	}
 
-#ifdef NO_ACCURATE_DIFF
-	if (oldsize > 0 && old[oldsize - 1] == '\n' &&
+	if (inaccurate_eof && oldsize > 0 && old[oldsize - 1] == '\n' &&
 			newsize > 0 && new[newsize - 1] == '\n') {
 		oldsize--;
 		newsize--;
 	}
-#endif
 
 	oldlines = old;
 	newlines = new;
@@ -1614,7 +1614,7 @@ static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
 		return apply_binary(desc, patch);
 
 	while (frag) {
-		if (apply_one_fragment(desc, frag) < 0)
+		if (apply_one_fragment(desc, frag, patch->inaccurate_eof) < 0)
 			return error("patch failed: %s:%ld",
 				     name, frag->oldpos);
 		frag = frag->next;
@@ -2097,7 +2097,7 @@ static int use_patch(struct patch *p)
 	return 1;
 }
 
-static int apply_patch(int fd, const char *filename)
+static int apply_patch(int fd, const char *filename, int inaccurate_eof)
 {
 	unsigned long offset, size;
 	char *buffer = read_patch_file(fd, &size);
@@ -2113,6 +2113,7 @@ static int apply_patch(int fd, const char *filename)
 		int nr;
 
 		patch = xcalloc(1, sizeof(*patch));
+		patch->inaccurate_eof = inaccurate_eof;
 		nr = parse_chunk(buffer + offset, size, patch);
 		if (nr < 0)
 			break;
@@ -2180,6 +2181,8 @@ int cmd_apply(int argc, const char **argv, char **envp)
 {
 	int i;
 	int read_stdin = 1;
+	int inaccurate_eof = 0;
+
 	const char *whitespace_option = NULL;
 
 	for (i = 1; i < argc; i++) {
@@ -2188,7 +2191,7 @@ int cmd_apply(int argc, const char **argv, char **envp)
 		int fd;
 
 		if (!strcmp(arg, "-")) {
-			apply_patch(0, "<stdin>");
+			apply_patch(0, "<stdin>", inaccurate_eof);
 			read_stdin = 0;
 			continue;
 		}
@@ -2265,6 +2268,10 @@ int cmd_apply(int argc, const char **argv, char **envp)
 			parse_whitespace_option(arg + 13);
 			continue;
 		}
+		if (!strcmp(arg, "--inaccurate-eof")) {
+			inaccurate_eof = 1;
+			continue;
+		}
 
 		if (check_index && prefix_length < 0) {
 			prefix = setup_git_directory();
@@ -2281,12 +2288,12 @@ int cmd_apply(int argc, const char **argv, char **envp)
 			usage(apply_usage);
 		read_stdin = 0;
 		set_default_whitespace_mode(whitespace_option);
-		apply_patch(fd, arg);
+		apply_patch(fd, arg, inaccurate_eof);
 		close(fd);
 	}
 	set_default_whitespace_mode(whitespace_option);
 	if (read_stdin)
-		apply_patch(0, "<stdin>");
+		apply_patch(0, "<stdin>", inaccurate_eof);
 	if (whitespace_error) {
 		if (squelch_whitespace_errors &&
 		    squelch_whitespace_errors < whitespace_error) {