From ad53a7dcd4d7152cda501934fe6489e4664839c6 Mon Sep 17 00:00:00 2001
From: gad <gad@FreeBSD.org>
Date: Fri, 26 Apr 2002 19:01:19 +0000
Subject: [PATCH] Modify our 'patch' utility to recognize the    \ No newline
 at end of file line that some versions of diff print out if the last line of
 the two files are different, and one of the two files does not have a newline
 character on that last line.

This change is still somewhat under discussion in -arch and -standards, but I
want to commit it to -current today so I'd have the chance to MFC it to -stable
before the code freeze for 4.6-release (which would be May 1st).

Note: the related change to 'diff' (so it might *generate* that line) is NOT
expected to be included in 4.6-release.  We can debate that change later.

Obtained from:	NetBSD (1.13 of basesrc/usr.bin/patch/pch.c, by kristerw)
MFC after:	4 days
---
 gnu/usr.bin/patch/pch.c | 64 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/gnu/usr.bin/patch/pch.c b/gnu/usr.bin/patch/pch.c
index 71bbd255c9ff..c9ab9cee8119 100644
--- a/gnu/usr.bin/patch/pch.c
+++ b/gnu/usr.bin/patch/pch.c
@@ -434,6 +434,30 @@ malformed ()
 		/* about as informative as "Syntax error" in C */
 }
 
+/*
+ * True if the line has been discarded (i.e. it is a line saying
+ *  "\ No newline at end of file".)
+ */
+static bool
+remove_special_line(void)
+{
+	int c;
+
+	c = fgetc(pfp);
+	if (c == '\\') {
+		do {
+			c = fgetc(pfp);
+		} while (c != EOF && c != '\n');
+
+		return TRUE;
+	}
+
+	if (c != EOF)
+		fseek(pfp, -1, SEEK_CUR);
+
+	return FALSE;
+}
+
 /* True if there is more of the current diff listing to process. */
 
 bool
@@ -641,6 +665,15 @@ another_hunk()
 		    p_end--;
 		    return FALSE;
 		}
+		if (p_end == p_ptrn_lines)
+		{
+			if (remove_special_line()) {
+				int len;
+
+				len = strlen(p_line[p_end]) - 1;
+				(p_line[p_end])[len] = 0;
+			}
+		}
 		break;
 	    case '\t': case '\n':	/* assume the 2 spaces got eaten */
 		if (repl_beginning && repl_could_be_missing &&
@@ -768,6 +801,14 @@ another_hunk()
 	    assert(fillsrc==p_end+1 || fillsrc==repl_beginning);
 	    assert(filldst==p_end+1 || filldst==repl_beginning);
 	}
+
+	if (p_line[p_end] != NULL)
+	{
+		if (remove_special_line()) {
+			p_len[p_end] -= 1;
+			(p_line[p_end])[p_len[p_end]] = 0;
+		}
+	}
     }
     else if (diff_type == UNI_DIFF) {
 	long line_beginning = ftell(pfp);
@@ -865,6 +906,12 @@ another_hunk()
 		p_Char[fillsrc] = ch;
 		p_line[fillsrc] = s;
 		p_len[fillsrc++] = strlen(s);
+		if (fillsrc > p_ptrn_lines) {
+			if (remove_special_line()) {
+				p_len[fillsrc - 1] -= 1;
+				s[p_len[fillsrc - 1]] = 0;
+			}
+		}
 		break;
 	    case '=':
 		ch = ' ';
@@ -900,6 +947,12 @@ another_hunk()
 		p_Char[filldst] = ch;
 		p_line[filldst] = s;
 		p_len[filldst++] = strlen(s);
+		if (fillsrc > p_ptrn_lines) {
+			if (remove_special_line()) {
+				p_len[filldst - 1] -= 1;
+				s[p_len[filldst - 1]] = 0;
+			}
+		}
 		break;
 	    default:
 		p_end = filldst;
@@ -975,6 +1028,12 @@ another_hunk()
 	    p_len[i] = strlen(p_line[i]);
 	    p_Char[i] = '-';
 	}
+
+	if (remove_special_line()) {
+		p_len[i-1] -= 1;
+		(p_line[i-1])[p_len[i-1]] = 0;
+	}
+
 	if (hunk_type == 'c') {
 	    ret = pgets(buf, sizeof buf, pfp);
 	    p_input_line++;
@@ -1007,6 +1066,11 @@ another_hunk()
 	    p_len[i] = strlen(p_line[i]);
 	    p_Char[i] = '+';
 	}
+
+	if (remove_special_line()) {
+		p_len[i-1] -= 1;
+		(p_line[i-1])[p_len[i-1]] = 0;
+	}
     }
     if (reverse)			/* backwards patch? */
 	if (!pch_swap())