From 55bbe8836df1bb8e521a6fb4e79a91d7e0702fb1 Mon Sep 17 00:00:00 2001
From: Chris Liddell <chris.liddell@artifex.com>
Date: Wed, 24 Apr 2013 08:27:41 +0100
Subject: Bug 693932 (related): generate meaningful error

Add a gp_fseekable() function, and use it to check the file object opened in
gdev_prn_open_printer_seekable(). If the file is not seekable, print an error
message and return an IOerror.

No cluster differences.
---
 gs/base/gp.h          |  2 ++
 gs/base/gp_mswin.c    | 15 +++++++++++++++
 gs/base/gp_os2.c      | 15 +++++++++++++++
 gs/base/gp_unifs.c    | 15 +++++++++++++++
 gs/base/gp_vms.c      | 15 +++++++++++++++
 gs/devices/gdevtifs.c |  5 +++++
 6 files changed, 67 insertions(+)

diff --git a/gs/base/gp.h b/gs/base/gp.h
index b09092df0..e9cccdb98 100644
--- a/gs/base/gp.h
+++ b/gs/base/gp.h
@@ -489,6 +489,8 @@ int64_t gp_ftell_64(FILE *strm);
 
 int gp_fseek_64(FILE *strm, int64_t offset, int origin);
 
+bool gp_fseekable (FILE *f);
+
 /* We don't define gp_fread_64, gp_fwrite_64,
    because (1) known platforms allow regular fread, fwrite
    to be applied to a file opened with O_LARGEFILE,
diff --git a/gs/base/gp_mswin.c b/gs/base/gp_mswin.c
index 00d97c882..fdbf3380a 100644
--- a/gs/base/gp_mswin.c
+++ b/gs/base/gp_mswin.c
@@ -829,6 +829,21 @@ int gp_fseek_64(FILE *strm, gs_offset_t offset, int origin)
 #endif
 }
 
+bool gp_fseekable (FILE *f)
+{
+    struct stat s;
+    int fno;
+    
+    fno = fileno(f);
+    if (fno < 0)
+        return(false);
+    
+    if (fstat(fno, &s) < 0)
+        return(false);
+
+    return((bool)S_ISREG(s.st_mode));
+}
+
 /* -------------------------  _snprintf -----------------------------*/
 
 /* Microsoft Visual C++ 2005  doesn't properly define snprintf,
diff --git a/gs/base/gp_os2.c b/gs/base/gp_os2.c
index eabbdb9d0..5a7b98e3b 100644
--- a/gs/base/gp_os2.c
+++ b/gs/base/gp_os2.c
@@ -617,3 +617,18 @@ int gp_fseek_64(FILE *strm, int64_t offset, int origin)
         return -1;
     return fseek(strm, offset1, origin);
 }
+
+bool gp_fseekable (FILE *f)
+{
+    struct stat s;
+    int fno;
+    
+    fno = fileno(f);
+    if (fno < 0)
+        return(false);
+    
+    if (fstat(fno, &s) < 0)
+        return(false);
+
+    return((bool)S_ISREG(s.st_mode));
+}
diff --git a/gs/base/gp_unifs.c b/gs/base/gp_unifs.c
index 340cb2f8b..eb13ae41c 100644
--- a/gs/base/gp_unifs.c
+++ b/gs/base/gp_unifs.c
@@ -544,3 +544,18 @@ int gp_fseek_64(FILE *strm, int64_t offset, int origin)
     return fseeko(strm, offset1, origin);
 #endif
 }
+
+bool gp_fseekable (FILE *f)
+{
+    struct stat s;
+    int fno;
+    
+    fno = fileno(f);
+    if (fno < 0)
+        return(false);
+    
+    if (fstat(fno, &s) < 0)
+        return(false);
+
+    return((bool)S_ISREG(s.st_mode));
+}
diff --git a/gs/base/gp_vms.c b/gs/base/gp_vms.c
index fdb22a7fe..cc79f4370 100644
--- a/gs/base/gp_vms.c
+++ b/gs/base/gp_vms.c
@@ -712,3 +712,18 @@ int gp_fseek_64(FILE *strm, int64_t offset, int origin)
         return -1;
     return fseek(strm, offset1, origin);
 }
+
+bool gp_fseekable (FILE *f)
+{
+    struct stat s;
+    int fno;
+    
+    fno = fileno(f);
+    if (fno < 0)
+        return(false);
+    
+    if (fstat(fno, &s) < 0)
+        return(false);
+
+    return((bool)S_ISREG(s.st_mode));
+}
diff --git a/gs/devices/gdevtifs.c b/gs/devices/gdevtifs.c
index d9d0bc8ae..9ccd9c4d9 100644
--- a/gs/devices/gdevtifs.c
+++ b/gs/devices/gdevtifs.c
@@ -60,6 +60,11 @@ tiff_output_page(gx_device *pdev, int num_copies, int flush)
         if (code < 0)
             return code;
 
+        if (!gp_fseekable(ppdev->file)) {
+            errprintf(pdev->memory, "I/O Error: Output File \"%s\" must be seekable\n", ppdev->fname);
+            return(gs_error_ioerror);
+        }
+
         /* If copypage request, try to do it using buffer_page */
         if ( !flush &&
              (*ppdev->printer_procs.buffer_page)
-- 
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