Attachment 694089 Details for Bug 615303 – Patch extracted from upstream less to fix the issue

[patch] Patch extracted from upstream less to fix the issue

less-436-empty-lessopen.patch (text/plain), 2.40 KB, created by Martin Bříza on 2013-02-06 18:33:15 UTC

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Creator: Martin Bříza

Created: 2013-02-06 18:33:15 UTC

Size: 2.40 KB

patch

obsolete

>--- less-436/less.nro.empty-lessopen	2013-02-06 19:16:06.640490749 +0100
>+++ less-436/less.nro	2013-02-06 19:16:06.649490726 +0100
>@@ -1147,11 +1147,26 @@ lesspipe.sh:
> .br
> 		;;
> .br
>+	*)	exit 1
>+.br
>+		;;
>+.br
> 	esac
> .br
>+	exit $?
>+.br
> .PP
> To use this script, put it where it can be executed and set
> LESSOPEN="|lesspipe.sh %s".
>+.PP
>+The script should return zero if the output was valid and non-zero
>+otherwise, so less could detect even a valid empty output
>+(for example while uncompressing gzipped empty file).
>+For backward-compatibility, this is not required by default. To turn
>+this functionality there should be another vertical bar (|) straight
>+after the first one in the LESSOPEN environment variable, eg.
>+LESSOPEN="||lesspipe.sh %s".
>+.PP
> When an input pipe is used, a LESSCLOSE postprocessor can be used,
> but it is usually not necessary since there is no replacement file
> to clean up.
>--- less-436/filename.c.empty-lessopen	2009-07-06 22:52:23.000000000 +0200
>+++ less-436/filename.c	2013-02-06 19:16:06.648490728 +0100
>@@ -843,6 +843,16 @@ open_altfile(filename, pf, pfd)
> #else
> 		lessopen++;
> 		returnfd = 1;
>+
>+		if (*lessopen == '|') {
>+			/*
>+			 * If there is another vertical bar |, after
>+			 * the first one, it indicates a "pipe preprocessor"
>+			 * with correct exit status.
>+			 */
>+			lessopen++;
>+			returnfd = 2;
>+		}
> #endif
> 	}
> 	if (*lessopen == '-') {
>@@ -879,17 +889,39 @@ open_altfile(filename, pf, pfd)
> 		 */
> 		f = fileno(fd);
> 		SET_BINARY(f);
>+		*pfd = (void *) fd;
>+		*pf = f;
> 		if (read(f, &c, 1) != 1)
> 		{
> 			/*
>-			 * Pipe is empty.  This means there is no alt file.
>+			 * Error or pipe is empty. Close it and eventually
>+			 * check exit status of the pipe process.
> 			 */
>-			pclose(fd);
>+			*pf = 0;
>+			*pfd = NULL;
>+			if (pclose(fd) == 0 && returnfd == 2) {
>+				/*
>+				 * Exit status was zero, so the EOF was correct empty output.
>+				 * Let the program open the archive again and seek to its end to
>+				 * be sure to get EOF.
>+				 * Quite ugly hack, to provide platform independency
>+				 */
>+				fd = fopen(filename, "rb");
>+				if (fd == NULL)
>+					return (NULL);
>+				int check_seek = fseek(fd, 0, SEEK_END);
>+				if (check_seek != 0)
>+				{
>+					fclose(fd);
>+					return (NULL);
>+				}
>+				*pf = fileno(fd);
>+				*pfd = (void *) fd;
>+				return (save(filename));
>+			}
> 			return (NULL);
> 		}
> 		ch_ungetchar(c);
>-		*pfd = (void *) fd;
>-		*pf = f;
> 		return (save("-"));
> 	}
> #endif

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Attachments on bug 615303: 467496 | 467503 | 514738 | 514739 | 694089