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[libpng15] Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
the sBIT fields in the test pixel as 0, which resulted in a floating point division by zero which was irrelevant but causes systems where FP exceptions cause a crash. Added code to pngvalid to turn on FP exceptions if the appropriate glibc support is there to ensure this is tested in the future.
This commit is contained in:
John Bowler
Glenn Randers-Pehrson
parent
88bcdc269b
commit
a004e23a4c
6
ANNOUNCE
6
ANNOUNCE
@ -49,6 +49,12 @@ Version 1.5.7beta02 [November 5, 2011]
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be non-NULL. The cast of the profile length potentially truncated the
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value unnecessarily on a 16-bit int system, so the cast of the (byte)
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compression type to (int) is specified by ANSI-C anyway.
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Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
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the sBIT fields in the test pixel as 0, which resulted in a floating
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point division by zero which was irrelevant but causes systems where
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FP exceptions cause a crash. Added code to pngvalid to turn on FP
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exceptions if the appropriate glibc support is there to ensure this is
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tested in the future.
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Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
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(subscription required; visit
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6
CHANGES
6
CHANGES
@ -3692,6 +3692,12 @@ Version 1.5.7beta02 [November 5, 2011]
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be non-NULL. The cast of the profile length potentially truncated the
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value unnecessarily on a 16-bit int system, so the cast of the (byte)
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compression type to (int) is specified by ANSI-C anyway.
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Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
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the sBIT fields in the test pixel as 0, which resulted in a floating
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point division by zero which was irrelevant but causes systems where
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FP exceptions cause a crash. Added code to pngvalid to turn on FP
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exceptions if the appropriate glibc support is there to ensure this is
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tested in the future.
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Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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(subscription required; visit
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10
png.h
10
png.h
@ -1,7 +1,7 @@
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/* png.h - header file for PNG reference library
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*
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* libpng version 1.5.7beta02 - November 4, 2011
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* libpng version 1.5.7beta02 - November 5, 2011
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* Copyright (c) 1998-2011 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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@ -11,7 +11,7 @@
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* Authors and maintainers:
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* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
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* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
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* libpng versions 0.97, January 1998, through 1.5.7beta02 - November 4, 2011: Glenn
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* libpng versions 0.97, January 1998, through 1.5.7beta02 - November 5, 2011: Glenn
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* See also "Contributing Authors", below.
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*
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* Note about libpng version numbers:
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@ -195,7 +195,7 @@
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*
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* This code is released under the libpng license.
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*
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* libpng versions 1.2.6, August 15, 2004, through 1.5.7beta02, November 4, 2011, are
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* libpng versions 1.2.6, August 15, 2004, through 1.5.7beta02, November 5, 2011, are
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* Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
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* distributed according to the same disclaimer and license as libpng-1.2.5
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* with the following individual added to the list of Contributing Authors:
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@ -307,7 +307,7 @@
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* Y2K compliance in libpng:
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* =========================
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*
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* November 4, 2011
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* November 5, 2011
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*
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* Since the PNG Development group is an ad-hoc body, we can't make
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* an official declaration.
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@ -370,7 +370,7 @@
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/* Version information for png.h - this should match the version in png.c */
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#define PNG_LIBPNG_VER_STRING "1.5.7beta02"
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#define PNG_HEADER_VERSION_STRING \
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" libpng version 1.5.7beta02 - November 4, 2011\n"
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" libpng version 1.5.7beta02 - November 5, 2011\n"
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#define PNG_LIBPNG_VER_SONUM 15
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#define PNG_LIBPNG_VER_DLLNUM 15
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121
pngvalid.c
121
pngvalid.c
@ -20,8 +20,21 @@
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*/
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#define _POSIX_SOURCE 1
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#define _ISOC99_SOURCE 1 /* For floating point */
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#define _GNU_SOURCE 1 /* For the floating point exception extension */
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#include <signal.h>
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_FEENABLEEXCEPT
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# include <fenv.h>
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#endif
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#include "png.h"
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#if PNG_LIBPNG_VER < 10500
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/* This delibarately lacks the PNG_CONST. */
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typedef png_byte *png_const_bytep;
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@ -831,6 +844,19 @@ store_log(png_store* ps, png_structp pp, png_const_charp message, int is_error)
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store_verbose(ps, pp, is_error ? "error: " : "warning: ", message);
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}
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/* Internal error function, called with a png_store but no libpng stuff. */
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static void
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internal_error(png_store *ps, png_const_charp message)
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{
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store_log(ps, NULL, message, 1 /* error */);
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/* And finally throw an exception. */
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{
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struct exception_context *the_exception_context = &ps->exception_context;
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Throw ps;
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}
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}
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/* Functions to use as PNG callbacks. */
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static void
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store_error(png_structp pp, png_const_charp message) /* PNG_NORETURN */
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@ -3679,9 +3705,11 @@ static PNG_CONST struct
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};
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static void
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make_error(png_store* volatile ps, png_byte PNG_CONST colour_type,
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make_error(png_store* volatile psIn, png_byte PNG_CONST colour_type,
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png_byte bit_depth, int interlace_type, int test, png_const_charp name)
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{
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png_store * volatile ps = psIn;
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context(ps, fault);
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Try
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@ -3965,6 +3993,8 @@ standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id,
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dp->ps = ps;
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dp->colour_type = COL_FROM_ID(id);
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dp->bit_depth = DEPTH_FROM_ID(id);
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if (dp->bit_depth < 1 || dp->bit_depth > 16)
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internal_error(ps, "internal: bad bit depth");
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if (dp->colour_type == 3)
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dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8;
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else
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@ -5333,8 +5363,12 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
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test_pixel.sample_depth = 8;
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else
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test_pixel.sample_depth = test_pixel.bit_depth;
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/* Don't need sBIT here */
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/* Don't need sBIT here, but it must be set to non-zero to avoid
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* arithmetic overflows.
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*/
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test_pixel.have_tRNS = dp->this.is_transparent;
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test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT =
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test_pixel.alpha_sBIT = test_pixel.sample_depth;
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dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp);
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@ -9267,6 +9301,72 @@ static PNG_CONST color_encoding test_encodings[] =
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/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} },
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};
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/* signal handler
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*
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* This attempts to trap signals and escape without crashing. It needs a
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* context pointer so that it can throw an exception (call longjmp) to recover
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* from the condition; this is handled by making the png_modifier used by 'main'
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* into a global variable.
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*/
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static png_modifier pm;
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static void signal_handler(int signum)
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{
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size_t pos = 0;
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char msg[64];
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pos = safecat(msg, sizeof msg, pos, "caught signal: ");
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switch (signum)
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{
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case SIGABRT:
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pos = safecat(msg, sizeof msg, pos, "abort");
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break;
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case SIGFPE:
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pos = safecat(msg, sizeof msg, pos, "floating point exception");
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break;
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case SIGILL:
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pos = safecat(msg, sizeof msg, pos, "illegal instruction");
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break;
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case SIGINT:
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pos = safecat(msg, sizeof msg, pos, "interrupt");
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break;
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case SIGSEGV:
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pos = safecat(msg, sizeof msg, pos, "invalid memory access");
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break;
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case SIGTERM:
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pos = safecat(msg, sizeof msg, pos, "termination request");
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break;
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default:
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pos = safecat(msg, sizeof msg, pos, "unknown ");
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pos = safecatn(msg, sizeof msg, pos, signum);
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break;
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}
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store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/);
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/* And finally throw an exception so we can keep going, unless this is
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* SIGTERM in which case stop now.
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*/
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if (signum != SIGTERM)
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{
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struct exception_context *the_exception_context =
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&pm.this.exception_context;
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Throw &pm.this;
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}
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else
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exit(1);
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}
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/* main program */
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int main(int argc, PNG_CONST char **argv)
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{
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@ -9288,9 +9388,24 @@ int main(int argc, PNG_CONST char **argv)
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size_t cp = 0;
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char command[1024];
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png_modifier pm;
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context(&pm.this, fault);
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/* Add appropriate signal handlers, just the ANSI specified ones: */
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signal(SIGABRT, signal_handler);
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signal(SIGFPE, signal_handler);
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signal(SIGILL, signal_handler);
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signal(SIGINT, signal_handler);
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signal(SIGSEGV, signal_handler);
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signal(SIGTERM, signal_handler);
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#ifdef HAVE_FEENABLEEXCEPT
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/* Only required to enable FP exceptions on platforms where they start off
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* disabled; this is not necessary but if it is not done pngvalid will likely
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* end up ignoring FP conditions that other platforms fault.
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*/
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feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW);
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#endif
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modifier_init(&pm);
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/* Preallocate the image buffer, because we know how big it needs to be,
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