Fix generating draco project files from a directory containing special characters

[whiteh0le]

If you try to generate draco project files from a directory containing any regex special characters cmake will fail.

In my case, draco is inside a directory called "c++" and, because "+" is a regex special character, cmake fails to generate the project files with the following error:

$ cmake ..
RegularExpression::compile(): Nested *?+.
RegularExpression::compile(): Error in compile.
CMake Error at cmake/draco_install.cmake:42 (list):
  list sub-command TRANSFORM, action REPLACE: Failed to compile regex
  "C:/repos/c++/draco/src/draco/".
Call Stack (most recent call first):
  CMakeLists.txt:1152 (draco_setup_install_target)

As you can see, the error occurs at line 42 of cmake/draco_install.cmake:

draco/cmake/draco_install.cmake

Line 42 in 931498a

list(TRANSFORM draco_api_includes REPLACE "${draco_src_root}/" "")

As per the cmake documentation, the REPLACE action of the TRANSFORM subcommand expects a regular expression as its first argument, in our case, this is the ${draco_src_root} variable containing the project's path.

The problem is that the code assumes that the directory path is a regex therefore it must not contain any special characters.

The solution is simple, replace the faulty list transform command by a directory-aware alternative. I choose the file RELATIVE_PATH command:

draco/cmake/draco_install.cmake

Lines 36 to 37 in 7577ec0

	file(RELATIVE_PATH relative_file ${draco_src_root} ${file})
	list(APPEND draco_api_includes ${relative_file})

This command will compute the relative path to the files correctly, even if the directory contains special characters.

With these changes cmake will now correctly generate the project files:

$ cmake ..
-- Configuring done (6.5s)
-- Generating done (1.1s)
-- Build files have been written to: C:/repos/c++/draco/build_dir

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