[PATCH 3/5] subsurface-configure.pri: add another libxml/libxslt detection stage

[Lubomir I. Ivanov]

From: "Lubomir I. Ivanov" <neolit123 at gmail.com>

libxml and libxslt use custom -config scripts which brake
qmake and make on Win32. The output of executing a .sh or .cmd
script with the same name produces garbled output. The output
of executables with the same name is untested, but a bit excessive
as a solution.

To work around the issue add another detection stage, which checks
if the previous output from (e.g.) xml2-config is empty and try
to use pkg-config instead.

Signed-off-by: Lubomir I. Ivanov <neolit123 at gmail.com>
---
 subsurface-configure.pri | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/subsurface-configure.pri b/subsurface-configure.pri
index 00222da..916bbdf 100644
--- a/subsurface-configure.pri
+++ b/subsurface-configure.pri
@@ -72,7 +72,16 @@ XML2_CFLAGS = $$system(xml2-config --cflags 2>$$NUL)
 XSLT_CFLAGS = $$system(xslt-config --cflags 2>$$NUL)
 XML2_LIBS = $$system(xml2-config --libs 2>$$NUL)
 XSLT_LIBS = $$system(xslt-config --libs 2>$$NUL)
+
 link_pkgconfig {
+    isEmpty(XML2_CFLAGS)|isEmpty(XML2_LIBS) {
+        XML2_CFLAGS = $$system(pkg-config --cflags libxml2 2> $$NUL)
+        XML2_LIBS = $$system(pkg-config --libs libxml2 2> $$NUL)
+    }
+    isEmpty(XSLT_CFLAGS)|isEmpty(XSLT_LIBS) {
+        XSLT_CFLAGS = $$system(pkg-config --cflags libxslt 2> $$NUL)
+        XSLT_LIBS = $$system(pkg-config --libs libxslt 2> $$NUL)
+    }
     isEmpty(XML2_CFLAGS)|isEmpty(XML2_LIBS): \
         error("Could not find libxml2. Did you forget to install it?")
     isEmpty(XSLT_CFLAGS)|isEmpty(XSLT_LIBS): \
-- 
1.7.11.msysgit.0