[tlbuild] dvi test?

[Paul Vojta]

Super!  Thank you, John and Bruno, for helping track down this bug.

Karl, could you please apply the attached patch to the current TeXLive tree?

Thanks!

Sincerely,


Paul Vojta


On Sat, Feb 12, 2022 at 01:03:30PM +0100, Bruno Voisin wrote:
> Paul wrote:
> 
> > Could someone try this out (on a Mac) and check whether the seek operation
> > still fails?  (This is relative to the latest dvi-init.c in the TeX Live
> > repository, from about 10 days ago.)
> 
> John answered:
> 
> > Yes, it does! That is, without the patch, r61850 produces:
> > 
> > jhawk at lrr xdvik % TEXMFROOT=/usr/local/texlive/2021 TEXMFCNF=$TEXMFROOT/texmf-dist/web2c  ./xdvi-bin t2a
> > xdvi-bin: Error: Couldn't seek to start of file /var/folders/m2/16zlwjgj2p5d3qdy99z2gzf40000gn/T/xdvi-oAjS3R: Invalid argument - disabling `useTempFp'; target_fp: 0x1dfbeed40.
> > 
> > And adding your patch to use dup() then produces no such output.
> 
> I can confirm this (on macOS 12.3 Beta 2, M1 chip, Xcode 13.2.1):
> 
> - Getting the latest sources and compiling them as is, I get
> 
> % env TEXMFROOT=/usr/local/texlive/2021 TEXMFCNF=/usr/local/texlive/2021/texmf-dist/web2c ./xdvi-bin ~/Desktop/Test/t2a.dvi
> [...]
> xdvi-bin: Error: Couldn't seek to start of file /var/folders/1r/dhdtft1s4qgfjwbcpkfhqf5c0000gn/T/xdvi-uAeCcl: Invalid argument - disabling `useTempFp'; target_fp: 0x1fdb51780.
> 
> - Applying your patch and compiling again, the error message vanishes.
> 
> Bruno
> 
-------------- next part --------------
--- dvi-init.c.orig	2022-02-01 18:05:30.000000000 -0800
+++ dvi-init.c	2022-02-12 19:21:57.472560593 -0800
@@ -1,6 +1,6 @@
 /*========================================================================*\
 
-Copyright (c) 1990-2013  Paul Vojta
+Copyright (c) 1990-2022  Paul Vojta
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to
@@ -1185,18 +1185,33 @@
 	ASSERT(target_fp != NULL, "");
 	ASSERT(source_fp != NULL, "");
 
-	if (fseek(target_fp, 0L, SEEK_SET)) {
+	tmp_fd = try_dup(fileno(target_fp));
+	if (tmp_fd == -1) {
+	    XDVI_ERROR((stderr, "Couldn't duplicate descriptor of file %s: %s - disabling `useTempFp'; target_fp: %p.",
+			m_tmp_dvi_name, strerror(errno), target_fp));
+	    goto fclose_and_fail;
+	}
+
+	fclose(target_fp);
+
+	if (lseek(tmp_fd, 0L, SEEK_SET) == -1) {
 	  XDVI_ERROR((stderr, "Couldn't seek to start of file %s: %s - disabling `useTempFp'; target_fp: %p.",
 			m_tmp_dvi_name, strerror(errno), target_fp));
-	  goto fclose_and_fail;
+	  goto fail;
 	}
 #if HAVE_FTRUNCATE
 	if (ftruncate(tmp_fd, 0) < 0) {
 	    XDVI_ERROR((stderr, "Couldn't truncate file %s: %s - disabling `useTempFp'; target_fp: %p.",
 			m_tmp_dvi_name, strerror(errno), target_fp));
-	    goto fclose_and_fail;
+	    goto fail;
 	}
 #endif
+
+	if ((target_fp = try_fdopen(tmp_fd, "wb+")) == NULL) {
+	    XDVI_ERROR((stderr, "error opening temporary file (%s) - disabling `useTempFp'.", strerror(errno)));
+	    goto fail;
+	}
+
 	if (fseek(source_fp, 0L, SEEK_SET)) {
 	  perror("fseek of source_fp");
 	  goto fclose_and_fail;
--- util.c.orig	2020-03-01 11:07:53.000000000 -0800
+++ util.c	2022-02-12 19:20:39.001805119 -0800
@@ -1,6 +1,6 @@
 /*========================================================================*\
 
-Copyright (c) 1990-2015  Paul Vojta and others
+Copyright (c) 1990-2022  Paul Vojta and others
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to
@@ -280,6 +280,20 @@
     }
     return fd;
 }
+
+/*
+ * Like try_fopen(), for dup().
+ */
+int
+try_dup(int oldfd)
+{
+    int fd = dup(oldfd);
+    if (fd < 0 && (errno == EMFILE || errno == ENFILE)) {
+	close_a_file();
+	fd = dup(oldfd);
+    }
+    return fd;
+}
 
 
 /*
--- util.h.orig	2016-04-05 15:50:13.000000000 -0700
+++ util.h	2022-02-12 19:21:24.379424206 -0800
@@ -51,6 +51,7 @@
 FILE *try_fdopen(int fd, const char *mode);
 int try_open(const char *fname, int flags);
 int try_open_mode(const char *fname, int flags, mode_t mode);
+int try_dup(int oldfd);
 
 extern int xdvi_temp_fd(char **tempfilename);
 extern void xdvi_assert(const char *version,