15097 2007-08-27 17:38:46 -0700 PNGImageDecoder.cpp throws away data in some cases 2007-08-29 10:37:38 -0700 1 1 1 Unclassified WebKit Images 523.x (Safari 3) PC All RESOLVED FIXED P2 Normal --- 0 pkasting webkit-unassigned oldest_to_newest 1365 0 pkasting 2007-08-27 17:38:46 -0700 The code in PNGImageDecoder.cpp (not used for Safari Mac/Win, but used by Cairo/QT) can throw away data when consumers call any decoding-related functions on it before frameBufferAtIndex(). This is because the libpng code will only decode incoming data once (it remembers it's already decoded the existing data when asked to decode it again), and if no frame buffer is set up when it makes its callbacks, the relevant data is simply discarded. And the frame buffer vector isn't resized to 1 frame (from 0) until frameBufferAtIndex() is called. I don't see a good reason for this. A single frame buffer entry takes up almost no memory before the underlying RGBA32Buffer is set up, so there really isn't a penalty for just sizing m_frameBufferCache to 1 in the constructor. This also saves some conditionals in various places that no longer need to worry about whether this vector is empty. Patch to fix coming shortly. 1366 1 16138 pkasting 2007-08-27 17:41:19 -0700 Created attachment 16138 patch v1 With this patch, consumers can call any function on the PNGImageDecoder and trust that the image data won't be discarded. 1299 2 16138 mjs 2007-08-28 21:20:29 -0700 Comment on attachment 16138 patch v1 r=me 1250 3 mrowe 2007-08-29 10:37:38 -0700 Landed in r25294. 16138 2007-08-27 17:41:19 -0700 2007-08-28 21:20:29 -0700 patch v1 patch text/plain 2798 pkasting SW5kZXg6IFdlYkNvcmUvQ2hhbmdlTG9nCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFdlYkNvcmUvQ2hhbmdlTG9n CShyZXZpc2lvbiAyNTI2NykKKysrIFdlYkNvcmUvQ2hhbmdlTG9nCSh3b3JraW5nIGNvcHkpCkBA IC0xLDMgKzEsMTkgQEAKKzIwMDctMDgtMjcgIFBldGVyIEthc3RpbmcgIDx6ZXJvZHB4QGdtYWls LmNvbT4KKworICAgICAgICBSZXZpZXdlZCBieSBOT0JPRFkgKE9PUFMhKS4KKworICAgICAgICAt IGZpeCBodHRwOi8vYnVncy53ZWJraXQub3JnL3Nob3dfYnVnLmNnaT9pZD0xNTA5NworCU1ha2Ug UE5HSW1hZ2VEZWNvZGVyLmNwcCBzaXplIGl0cyBmcmFtZSBidWZmZXIgdmVjdG9yIGluIGl0cwor CWNvbnN0cnVjdG9yLCBzbyBpdCBuZXZlciB0aHJvd3MgZGVjb2RlZCBpbWFnZSBkYXRhIGF3YXkg bm8gbWF0dGVyCisJd2hhdCBvcmRlciBpdHMgZnVuY3Rpb25zIGFyZSBjYWxsZWQgaW4uCisKKyAg ICAgICAgKiBwbGF0Zm9ybS9pbWFnZS1kZWNvZGVycy9wbmcvUE5HSW1hZ2VEZWNvZGVyLmNwcDoK KyAgICAgICAgKFdlYkNvcmU6OlBOR0ltYWdlRGVjb2Rlcjo6UE5HSW1hZ2VEZWNvZGVyKToKKyAg ICAgICAgKFdlYkNvcmU6OlBOR0ltYWdlRGVjb2Rlcjo6ZnJhbWVCdWZmZXJBdEluZGV4KToKKyAg ICAgICAgKFdlYkNvcmU6OlBOR0ltYWdlRGVjb2Rlcjo6ZGVjb2RlKToKKyAgICAgICAgKFdlYkNv cmU6OlBOR0ltYWdlRGVjb2Rlcjo6cm93QXZhaWxhYmxlKToKKyAgICAgICAgKFdlYkNvcmU6OlBO R0ltYWdlRGVjb2Rlcjo6cG5nQ29tcGxldGUpOgorCiAyMDA3LTA4LTI3ICBBbnR0aSBLb2l2aXN0 byAgPGFudHRpQGFwcGxlLmNvbT4KIAogICAgICAgICBSZXZpZXdlZCBieSBNYWNpZWouCkluZGV4 OiBXZWJDb3JlL3BsYXRmb3JtL2ltYWdlLWRlY29kZXJzL3BuZy9QTkdJbWFnZURlY29kZXIuY3Bw Cj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT0KLS0tIFdlYkNvcmUvcGxhdGZvcm0vaW1hZ2UtZGVjb2RlcnMvcG5nL1BOR0lt YWdlRGVjb2Rlci5jcHAJKHJldmlzaW9uIDI1MjY3KQorKysgV2ViQ29yZS9wbGF0Zm9ybS9pbWFn ZS1kZWNvZGVycy9wbmcvUE5HSW1hZ2VEZWNvZGVyLmNwcAkod29ya2luZyBjb3B5KQpAQCAtMTM0 LDcgKzEzNCw5IEBAIHByaXZhdGU6CiAKIFBOR0ltYWdlRGVjb2Rlcjo6UE5HSW1hZ2VEZWNvZGVy KCkKIDogbV9yZWFkZXIoMCkKLXt9Cit7CisgICAgbV9mcmFtZUJ1ZmZlckNhY2hlLnJlc2l6ZSgx KTsKK30KIAogUE5HSW1hZ2VEZWNvZGVyOjp+UE5HSW1hZ2VEZWNvZGVyKCkKIHsKQEAgLTE3Niw5 ICsxNzgsNiBAQCBSR0JBMzJCdWZmZXIqIFBOR0ltYWdlRGVjb2Rlcjo6ZnJhbWVCdWZmCiAgICAg aWYgKGluZGV4KQogICAgICAgICByZXR1cm4gMDsKIAotICAgIGlmIChtX2ZyYW1lQnVmZmVyQ2Fj aGUuaXNFbXB0eSgpKQotICAgICAgICBtX2ZyYW1lQnVmZmVyQ2FjaGUucmVzaXplKDEpOwotCiAg ICAgUkdCQTMyQnVmZmVyJiBmcmFtZSA9IG1fZnJhbWVCdWZmZXJDYWNoZVswXTsKICAgICBpZiAo ZnJhbWUuc3RhdHVzKCkgIT0gUkdCQTMyQnVmZmVyOjpGcmFtZUNvbXBsZXRlICYmIG1fcmVhZGVy KQogICAgICAgICAvLyBEZWNvZGUgdGhpcyBmcmFtZS4KQEAgLTE5NCw3ICsxOTMsNyBAQCB2b2lk IFBOR0ltYWdlRGVjb2Rlcjo6ZGVjb2RlKGJvb2wgc2l6ZU9uCiAKICAgICBtX3JlYWRlci0+ZGVj b2RlKG1fZGF0YSwgc2l6ZU9ubHkpOwogICAgIAotICAgIGlmIChtX2ZhaWxlZCB8fCAoIW1fZnJh bWVCdWZmZXJDYWNoZS5pc0VtcHR5KCkgJiYgbV9mcmFtZUJ1ZmZlckNhY2hlWzBdLnN0YXR1cygp ID09IFJHQkEzMkJ1ZmZlcjo6RnJhbWVDb21wbGV0ZSkpIHsKKyAgICBpZiAobV9mYWlsZWQgfHwg KG1fZnJhbWVCdWZmZXJDYWNoZVswXS5zdGF0dXMoKSA9PSBSR0JBMzJCdWZmZXI6OkZyYW1lQ29t cGxldGUpKSB7CiAgICAgICAgIGRlbGV0ZSBtX3JlYWRlcjsKICAgICAgICAgbV9yZWFkZXIgPSAw OwogICAgIH0KQEAgLTMwMiw5ICszMDEsNiBAQCB2b2lkIHJvd0F2YWlsYWJsZShwbmdfc3RydWN0 cCBwbmcsIHBuZ19iCiAKIHZvaWQgUE5HSW1hZ2VEZWNvZGVyOjpyb3dBdmFpbGFibGUodW5zaWdu ZWQgY2hhciogcm93QnVmZmVyLCB1bnNpZ25lZCByb3dJbmRleCwgaW50IGludGVybGFjZVBhc3Mp CiB7Ci0gICAgaWYgKG1fZnJhbWVCdWZmZXJDYWNoZS5pc0VtcHR5KCkpCi0gICAgICAgIHJldHVy bjsKLQogICAgIC8vIFJlc2l6ZSB0byB0aGUgd2lkdGggYW5kIGhlaWdodCBvZiB0aGUgaW1hZ2Uu CiAgICAgUkdCQTMyQnVmZmVyJiBidWZmZXIgPSBtX2ZyYW1lQnVmZmVyQ2FjaGVbMF07CiAgICAg aWYgKGJ1ZmZlci5zdGF0dXMoKSA9PSBSR0JBMzJCdWZmZXI6OkZyYW1lRW1wdHkpIHsKQEAgLTM5 MSw5ICszODcsNiBAQCB2b2lkIHBuZ0NvbXBsZXRlKHBuZ19zdHJ1Y3RwIHBuZywgcG5nX2luCiAK IHZvaWQgUE5HSW1hZ2VEZWNvZGVyOjpwbmdDb21wbGV0ZSgpCiB7Ci0gICAgaWYgKG1fZnJhbWVC dWZmZXJDYWNoZS5pc0VtcHR5KCkpCi0gICAgICAgIHJldHVybjsKLQogICAgIC8vIEhhbmQgYmFj ayBhbiBhcHByb3ByaWF0ZWx5IHNpemVkIGJ1ZmZlciwgZXZlbiBpZiB0aGUgaW1hZ2UgZW5kZWQg dXAgYmVpbmcgZW1wdHkuCiAgICAgUkdCQTMyQnVmZmVyJiBidWZmZXIgPSBtX2ZyYW1lQnVmZmVy Q2FjaGVbMF07CiAgICAgYnVmZmVyLnNldFN0YXR1cyhSR0JBMzJCdWZmZXI6OkZyYW1lQ29tcGxl dGUpOwo=