fix: ImageOutput::check_open logic was flawed

src/include/OpenImageIO/imageio.h

@@ -2164,11 +2164,12 @@ class OIIO_API ImageInput {
     ///     The ImageSpec that we are validating.
     ///
     /// @param range
-    ///     An ROI that describes the allowable pixel coordinates and channel
-    ///     indices as half-open intervals.  For example, the default value
-    ///     `{0, 65535, 0, 65535, 0, 1, 0, 4}` means that pixel coordinates
-    ///     must be non-negative and the width and height be representable by
-    ///     a uint16 value, up to 4 channels are allowed, and volumes are not
+    ///     An ROI that describes the allowable resolution and channel count:
+    ///     the width, height, depth, and channel count of the ROI are the
+    ///     maximum allowed for the file type. For example, the default value
+    ///     `{0, 65535, 0, 65535, 0, 1, 0, 4}` means that pixel data width
+    ///     and height must be non-negative and representable by uint16
+    ///     values, up to 4 channels are allowed, and volumes are not
     ///     permitted (z coordinate may only be 0). File formats that can
     ///     handle larger resolutions, or volumes, or >4 channels must
     ///     override these limits!

src/libOpenImageIO/imageoutput.cpp

@@ -1124,24 +1124,6 @@ ImageOutput::check_open(OpenMode mode, const ImageSpec& userspec, ROI range,
                 m_spec.z = 0;
             }
         }
-        if (m_spec.x < range.xbegin || m_spec.x + m_spec.width > range.xend
-            || m_spec.y < range.ybegin || m_spec.y + m_spec.height > range.yend
-            || m_spec.z < range.zbegin
-            || m_spec.z + m_spec.depth > range.zend) {
-            if (m_spec.depth == 1)
-                errorfmt(
-                    "{} requested pixel data window [{}, {}) x [{}, {}) exceeds the allowable range of [{}, {}) x [{}, {})",
-                    format_name(), m_spec.x, m_spec.x + m_spec.width, m_spec.y,
-                    m_spec.y + m_spec.height, range.xbegin, range.xend,
-                    range.ybegin, range.yend);
-            else
-                errorfmt(
-                    "{} requested pixel data window [{}, {}) x [{}, {}) x [{}, {}) exceeds the allowable range of [{}, {}) x [{}, {}) x [{}, {})\n{} vs {}\n",
-                    format_name(), m_spec.x, m_spec.x + m_spec.width, m_spec.y,
-                    m_spec.y + m_spec.height, m_spec.z, m_spec.z + m_spec.depth,
-                    range.xbegin, range.xend, range.ybegin, range.yend,
-                    range.zbegin, range.zend);
-        }
     }
 
     if (m_spec.extra_attribs.contains("ioproxy") && !supports("ioproxy")) {

src/openexr.imageio/exrinput.cpp

@@ -1351,8 +1351,8 @@ OpenEXRInput::read_native_tiles(int subimage, int miplevel, int xbegin,
         tmpbuf.resize(nxtiles * nytiles * m_spec.tile_bytes(true));
         data = tmpbuf.data();
     }
-    char* buf = (char*)data - xbegin * pixelbytes
-                - ybegin * pixelbytes * m_spec.tile_width * nxtiles;
+    char* buf = (char*)data - ptrdiff_t(xbegin * pixelbytes)
+                - ptrdiff_t(ybegin * pixelbytes * m_spec.tile_width * nxtiles);
 
     try {
         Imf::FrameBuffer frameBuffer;

src/openexr.imageio/exroutput.cpp

@@ -375,7 +375,8 @@ OpenEXROutput::open(const std::string& name, const ImageSpec& userspec,
         m_nmiplevels = 1;
         m_miplevel   = 0;
         m_headers.resize(1);
-        copy_and_check_spec(userspec, m_spec);
+        if (!copy_and_check_spec(userspec, m_spec))
+            return false;
         sanity_check_channelnames();
         const ParamValue* param = m_spec.find_attribute("oiio:ioproxy",
                                                         TypeDesc::PTR);
@@ -1317,7 +1318,7 @@ OpenEXROutput::sanity_check_channelnames()
             if (m_spec.channelnames[c].empty()
                 || m_spec.channelnames[c] == m_spec.channelnames[i]) {
                 // Duplicate or missing channel name! We don't want
-                // libIlmImf to drop the channel (as it will do for
+                // libOpenEXR to drop the channel (as it will do for
                 // duplicates), so rename it and hope for the best.
                 m_spec.channelnames[c] = Strutil::fmt::format("channel{}", c);
                 break;
@@ -1380,7 +1381,8 @@ OpenEXROutput::write_scanline(int y, int z, TypeDesc format, const void* data,
     // where the address of the "virtual framebuffer" for the whole
     // image.
     imagesize_t scanlinebytes = m_spec.scanline_bytes(native);
-    char* buf = (char*)data - m_spec.x * pixel_bytes - y * scanlinebytes;
+    char* buf                 = (char*)data - ptrdiff_t(m_spec.x * pixel_bytes)
+                - ptrdiff_t(y * scanlinebytes);
 
     try {
         Imf::FrameBuffer frameBuffer;
@@ -1643,7 +1645,8 @@ OpenEXROutput::write_tiles(int xbegin, int xend, int ybegin, int yend,
         data = &padded[0];
     }
 
-    char* buf = (char*)data - xbegin * pixelbytes - ybegin * widthbytes;
+    char* buf = (char*)data - ptrdiff_t(xbegin * pixelbytes)
+                - ptrdiff_t(ybegin * widthbytes);
 
     try {
         Imf::FrameBuffer frameBuffer;

testsuite/openexr-suite/ref/out.txt

@@ -347,3 +347,17 @@ Reading ../openexr-images/Beachball/singlepart.0001.exr
     openexr:lineOrder: "increasingY"
 Comparing "../openexr-images/Beachball/singlepart.0001.exr" and "singlepart.0001.exr"
 PASS
+Reading negoverscan.exr
+negoverscan.exr      :   64 x   64, 3 channel, half openexr
+    SHA-1: EBDD38B69CD5B9F2D00D273C981E16960FBBB4F7
+    channel list: R, G, B
+    pixel data origin: x=-16, y=-16
+    full/display size: 64 x 64
+    full/display origin: -16, -16
+    compression: "zip"
+    PixelAspectRatio: 1
+    screenWindowCenter: 0, 0
+    screenWindowWidth: 1
+    oiio:ColorSpace: "lin_rec709"
+    oiio:subimages: 1
+    openexr:lineOrder: "increasingY"

testsuite/openexr-suite/run.py

@@ -4,6 +4,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # https://github.com/AcademySoftwareFoundation/OpenImageIO
 
+redirect = " >> out.txt 2>&1"
+
 # ../openexr-images/ScanLines:
 # Blobbies.exr     Cannon.exr  MtTamWest.exr     StillLife.exr
 # CandleGlass.exr  Desk.exr    PrismsLenses.exr  Tree.exr
@@ -44,3 +46,7 @@
 files = [ "singlepart.0001.exr" ]
 for f in files:
     command += rw_command (imagedir, f)
+
+# Check writing overscan and negative range
+command += oiiotool("--create 64x64-16-16 3 -d half -o negoverscan.exr")
+command += info_command("negoverscan.exr", safematch=True)