Fix some wrong behavior with sysroot option.

Fix reading the outdated caches.
Apply a patch to make it MT-safe more.

FcConfigGetFilename.3

@@ -0,0 +1,25 @@
+.\" auto-generated by docbook2man-spec from docbook-utils package
+.TH "FcConfigGetFilename" "3" "27 1月 2020" "Fontconfig 2.13.91" ""
+.SH NAME
+FcConfigGetFilename \- Find a config file
+.SH SYNOPSIS
+.nf
+\fB#include <fontconfig/fontconfig.h>
+.sp
+FcChar8 * FcConfigGetFilename (FcConfig *\fIconfig\fB, const FcChar8 *\fIname\fB);
+.fi\fR
+.SH "DESCRIPTION"
+.PP
+Given the specified external entity name, return the associated filename.
+This provides applications a way to convert various configuration file
+references into filename form.
+.PP
+A null or empty \fIname\fR indicates that the default configuration file should
+be used; which file this references can be overridden with the
+FONTCONFIG_FILE environment variable. Next, if the name starts with \fI~\fR, it
+refers to a file in the current users home directory. Otherwise if the name
+doesn't start with '/', it refers to a file in the default configuration
+directory; the built-in default directory can be overridden with the
+FONTCONFIG_PATH environment variable.
+.PP
+The result of this function is affected by the FONTCONFIG_SYSROOT environment variable or equivalent functionality.

fontconfig.spec

@@ -15,6 +15,7 @@ Source:		http://fontconfig.org/release/%{name}-%{version}.tar.xz
 URL:		http://fontconfig.org
 Source1:	25-no-bitmap-fedora.conf
 Source2:	fc-cache
+Source3:	FcConfigGetFilename.3
 
 # https://bugzilla.redhat.com/show_bug.cgi?id=140335
 Patch0:		%{name}-sleep-less.patch
@@ -68,6 +69,7 @@ which is useful for developing applications that uses fontconfig.
 
 %prep
 %autosetup -p1
+cp %{SOURCE3} $RPM_BUILD_DIR/%{name}-%{version}/doc
 
 %build
 # We don't want to rebuild the docs, but we want to install the included ones.