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| Known bugs and suggested enhancements in libpng-1.0.6 |
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| 1. April 1, 2000 -- BUG |
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| Under some circumstances old applications that make direct access to |
| the info_ptr->text and its members might free the same memory that |
| is also free'ed by libpng during the png_destroy_struct process. |
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| Fixed in libpng-1.0.6-patch-03 and libpng-1.0.6d. The PNG_FREE_TEXT flag |
| bit in info_ptr->free_me is now checked to make sure libpng is responsible |
| for freeing the memory. |
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| 2. April 1, 2000 -- BUG |
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| The non-ISO-C "strdup()" function is used in png.c |
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| STATUS: The function has been simplified and no longer uses strdup() |
| in libpng-1.0.6-patch-03 and libpng-1.0.6d. |
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| 3. March 24, 2000 -- BUG |
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| The png_set_rgb_to_gray_fixed() function is setting incorrect weighting |
| factors. |
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| STATUS: Fixed in libpng-1.0.6-patch-02 and libpng-1.0.6d. |
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| 4. March 22, 2000 -- BUG |
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| There are some printf() and fprintf() statements active in pngwutil.c |
| when PNG_NO_STDIO and PNG_sCAL_SUPPORTED are both defined. |
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| STATUS: Fixed in libpng-1.0.6-patch-01 and libpng-1.0.6d. The strcpy() |
| function is used instead. |
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| 5. March 22, 2000 -- BUG |
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| The length of the iCCP chunk data is calculated incorrectly; because |
| it can contain zeroes, strlen() doesn't work. |
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| STATUS: Fixed in libpng-1.0.6-patch-01 and libpng-1.0.6d by adding a |
| data_length parameter to the png_decompress_chunk() function. |
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| 6. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey |
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| Loops need to be optimized everywhere |
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| Make them count down instead of up -- Kevin Bracey |
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| Optimizing compilers don't need this, and making |
| the change would be error prone -- Tom Lane, Glenn R-P |
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| Question whether i-- or --i is better. |
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| STATUS: Under investigation, postponed until after |
| libpng-1.1.0. About 160 loops will be turned around |
| in libpng-1.1.Nn, for testing. |
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| 7. July 4, 1998 -- ENHANCEMENT -- Glenn R-P |
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| libpng-1.0.5 and earlier transform colors to gamma=1.0 space for |
| merging with background, and then back to the image's gamma. The |
| bit_depth of the intermediate (gamma=1.0) representation is probably |
| not sufficient. In the typical gamma=1/2.2 situation, the linear |
| pixels need about 4 more bits than the gamma-encoded ones, to avoid |
| loss of precision. A similar situation exists with the rgb_to_gray |
| operation. |
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| STATUS: under development. |
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| 8. September 1999 -- ENHANCEMENT -- |
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| It should be possible to use libpng without floating-point aritmetic. |
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| STATUS: Under investigation, implementation postponed until after |
| libpng-1.0.6. The application interface will change because replacements |
| for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_() |
| functions will be needed. |
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| Much of this was completed in libpng-1.0.6, but gamma compensation |
| is not yet done in fixed-point arithmetic. |
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