From 96d68291af30586e0f5ce80b46d5d4e503af15a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-S=C3=A9bastien=20P=C3=A9dron?= <dumbbell@FreeBSD.org>
Date: Fri, 8 Aug 2014 17:29:01 +0000
Subject: [PATCH] sed(1): Don't force a newline on last line, if input stream
 doesn't have one

While here, change how we check if the current line is the last one.
Before, we just checked if there were more files after the current one.
Now, we check the actual content of those files: they files may not have
a line at all. This matches the definition of the "last line" by the
Open Group.

The new behavior is closer to GNU sed.

PR:		160745
Phabric:	https://phabric.freebsd.org/D431
Reviewed by:	jilles
Approved by:	jilles
Exp-run by:	antoine
---
 usr.bin/sed/defs.h              |  1 +
 usr.bin/sed/main.c              | 50 +++++++++++++++++++++++++++++----
 usr.bin/sed/process.c           | 16 +++++++++--
 usr.bin/sed/tests/regress.y.out |  2 +-
 4 files changed, 61 insertions(+), 8 deletions(-)

diff --git a/usr.bin/sed/defs.h b/usr.bin/sed/defs.h
index d4f434ee84eb..fb336765d639 100644
--- a/usr.bin/sed/defs.h
+++ b/usr.bin/sed/defs.h
@@ -143,6 +143,7 @@ typedef struct {
 	char *space;		/* Current space pointer. */
 	size_t len;		/* Current length. */
 	int deleted;		/* If deleted. */
+	int append_newline;	/* If originally terminated by \n. */
 	char *back;		/* Backing memory. */
 	size_t blen;		/* Backing memory length. */
 } SPACE;
diff --git a/usr.bin/sed/main.c b/usr.bin/sed/main.c
index 6cdfcda93678..76e186f96b8a 100644
--- a/usr.bin/sed/main.c
+++ b/usr.bin/sed/main.c
@@ -439,8 +439,14 @@ mf_fgets(SPACE *sp, enum e_spflag spflag)
 	len = getline(&p, &plen, infile);
 	if (len == -1)
 		err(1, "%s", fname);
-	if (len != 0 && p[len - 1] == '\n')
+	if (len != 0 && p[len - 1] == '\n') {
+		sp->append_newline = 1;
 		len--;
+	} else if (!lastline()) {
+		sp->append_newline = 1;
+	} else {
+		sp->append_newline = 0;
+	}
 	cspace(sp, p, len, spflag);
 
 	linenum++;
@@ -481,15 +487,49 @@ add_file(char *s)
 	fl_nextp = &fp->next;
 }
 
+static int
+next_files_have_lines()
+{
+	struct s_flist *file;
+	FILE *file_fd;
+	int ch;
+
+	file = files;
+	while ((file = file->next) != NULL) {
+		if ((file_fd = fopen(file->fname, "r")) == NULL)
+			continue;
+
+		if ((ch = getc(file_fd)) != EOF) {
+			/*
+			 * This next file has content, therefore current
+			 * file doesn't contains the last line.
+			 */
+			ungetc(ch, file_fd);
+			fclose(file_fd);
+			return (1);
+		}
+
+		fclose(file_fd);
+	}
+
+	return (0);
+}
+
 int
 lastline(void)
 {
 	int ch;
 
-	if (files->next != NULL && (inplace == NULL || ispan))
-		return (0);
-	if ((ch = getc(infile)) == EOF)
-		return (1);
+	if (feof(infile)) {
+		return !(
+		    (inplace == NULL || ispan) &&
+		    next_files_have_lines());
+	}
+	if ((ch = getc(infile)) == EOF) {
+		return !(
+		    (inplace == NULL || ispan) &&
+		    next_files_have_lines());
+	}
 	ungetc(ch, infile);
 	return (0);
 }
diff --git a/usr.bin/sed/process.c b/usr.bin/sed/process.c
index a500200dd87d..9cd2c2e87b24 100644
--- a/usr.bin/sed/process.c
+++ b/usr.bin/sed/process.c
@@ -63,6 +63,7 @@ static SPACE HS, PS, SS, YS;
 #define	pd		PS.deleted
 #define	ps		PS.space
 #define	psl		PS.len
+#define	psanl		PS.append_newline
 #define	hs		HS.space
 #define	hsl		HS.len
 
@@ -85,7 +86,10 @@ static regex_t *defpreg;
 size_t maxnsub;
 regmatch_t *match;
 
-#define OUT() do {fwrite(ps, 1, psl, outfile); fputc('\n', outfile);} while (0)
+#define OUT() do {							\
+	fwrite(ps, 1, psl, outfile);					\
+	if (psanl) fputc('\n', outfile);				\
+} while (0)
 
 void
 process(void)
@@ -94,6 +98,7 @@ process(void)
 	SPACE tspace;
 	size_t oldpsl = 0;
 	char *p;
+	int oldpsanl;
 
 	p = NULL;
 
@@ -190,11 +195,15 @@ process(void)
 					break;
 				if ((p = memchr(ps, '\n', psl)) != NULL) {
 					oldpsl = psl;
+					oldpsanl = psanl;
 					psl = p - ps;
+					psanl = 1;
 				}
 				OUT();
-				if (p != NULL)
+				if (p != NULL) {
 					psl = oldpsl;
+					psanl = oldpsanl;
+				}
 				break;
 			case 'q':
 				if (!nflag && !pd)
@@ -244,6 +253,7 @@ process(void)
 					cspace(&HS, "", 0, REPLACE);
 				tspace = PS;
 				PS = HS;
+				psanl = tspace.append_newline;
 				HS = tspace;
 				break;
 			case 'y':
@@ -452,6 +462,7 @@ substitute(struct s_command *cp)
 	 */
 	tspace = PS;
 	PS = SS;
+	psanl = tspace.append_newline;
 	SS = tspace;
 	SS.space = SS.back;
 
@@ -521,6 +532,7 @@ do_tr(struct s_tr *y)
 		/* Swap the translation space and the pattern space. */
 		tmp = PS;
 		PS = YS;
+		psanl = tmp.append_newline;
 		YS = tmp;
 		YS.space = YS.back;
 	}
diff --git a/usr.bin/sed/tests/regress.y.out b/usr.bin/sed/tests/regress.y.out
index 829a68180276..22f4f051cef1 100644
--- a/usr.bin/sed/tests/regress.y.out
+++ b/usr.bin/sed/tests/regress.y.out
@@ -1 +1 @@
-fOO
+fOO
\ No newline at end of file