xmlcatalog: restore ability to query system catalog easily

I've noticed that easy way of locating a DocBook XSLT in a configure
script of another project doesn't work anymore.  It is using something
like: xmlcatalog "" ${DOCBOOK_XSL_URI}/${DOCBOOK_XSL_PATH}.  The script
is then forced to a plain, suboptimal search using find utility.
Indeed, I retrospectively realize that the check was working just
by mere accident given that the window this presumably side-effect
was applicable had not lasted long, some 8 months between

  054c716ea1bf001544127a4ab4f4346d1b9947e7

introducing xmlInitializeCatalog in the LIBXML_TEST_VERSION-rooted
call chain, and

  f65128f38289d77ff322d63aef2858cc0a819c34

reverting that again.

So while one can state /etc/xml/catalog constant explicitly, in
some use cases (such as the mentioned one -- that's why I wanted
to omit stating the full path in the first place), this is rather
an implementation detail, perhaps subject to change from that POV.
Therefore I propose to restore that behaviour in the targeted
manner without global disruptions this time around.

As a side-effect, this fixes indenting of the affected part.
1 file changed
tree: 66cc1bb9cdfb4d005a7e6775a7252125ec235964
  1. bakefile/
  2. doc/
  3. example/
  4. include/
  5. macos/
  6. optim/
  7. os400/
  8. python/
  9. result/
  10. test/
  11. vms/
  12. VxWorks/
  13. win32/
  14. xstc/
  15. .gitignore
  16. .travis.yml
  17. acinclude.m4
  18. AUTHORS
  19. autogen.sh
  20. buf.c
  21. buf.h
  22. build_glob.py
  23. c14n.c
  24. catalog.c
  25. ChangeLog
  26. check-relaxng-test-suite.py
  27. check-relaxng-test-suite2.py
  28. check-xinclude-test-suite.py
  29. check-xml-test-suite.py
  30. check-xsddata-test-suite.py
  31. chvalid.c
  32. chvalid.def
  33. configure.ac
  34. Copyright
  35. dbgen.pl
  36. dbgenattr.pl
  37. debugXML.c
  38. dict.c
  39. DOCBparser.c
  40. elfgcchack.h
  41. enc.h
  42. encoding.c
  43. entities.c
  44. error.c
  45. genChRanges.py
  46. gentest.py
  47. genUnicode.py
  48. global.data
  49. globals.c
  50. HACKING
  51. hash.c
  52. HTMLparser.c
  53. HTMLtree.c
  54. INSTALL.libxml2
  55. legacy.c
  56. libxml-2.0-uninstalled.pc.in
  57. libxml-2.0.pc.in
  58. libxml.3
  59. libxml.h
  60. libxml.m4
  61. libxml.spec.in
  62. libxml2-config.cmake.in
  63. libxml2.doap
  64. libxml2.syms
  65. list.c
  66. MAINTAINERS
  67. Makefile.am
  68. Makefile.tests
  69. Makefile.win
  70. nanoftp.c
  71. nanohttp.c
  72. NEWS
  73. parser.c
  74. parserInternals.c
  75. pattern.c
  76. README
  77. README.cvs-commits
  78. README.tests
  79. README.zOS
  80. regressions.py
  81. regressions.xml
  82. relaxng.c
  83. rngparser.c
  84. runsuite.c
  85. runtest.c
  86. runxmlconf.c
  87. save.h
  88. SAX.c
  89. SAX2.c
  90. schematron.c
  91. testapi.c
  92. testAutomata.c
  93. testC14N.c
  94. testchar.c
  95. testdict.c
  96. testdso.c
  97. testHTML.c
  98. testlimits.c
  99. testModule.c
  100. testOOM.c
  101. testOOMlib.c
  102. testOOMlib.h
  103. testReader.c
  104. testrecurse.c
  105. testRegexp.c
  106. testRelax.c
  107. testSAX.c
  108. testSchemas.c
  109. testThreads.c
  110. testThreadsWin32.c
  111. testURI.c
  112. testXPath.c
  113. threads.c
  114. timsort.h
  115. TODO
  116. TODO_SCHEMAS
  117. tree.c
  118. trio.c
  119. trio.h
  120. triodef.h
  121. trionan.c
  122. trionan.h
  123. triop.h
  124. triostr.c
  125. triostr.h
  126. uri.c
  127. valid.c
  128. xinclude.c
  129. xlink.c
  130. xml2-config.1
  131. xml2-config.in
  132. xml2Conf.sh.in
  133. xmlcatalog.c
  134. xmlIO.c
  135. xmllint.c
  136. xmlmemory.c
  137. xmlmodule.c
  138. xmlreader.c
  139. xmlregexp.c
  140. xmlsave.c
  141. xmlschemas.c
  142. xmlschemastypes.c
  143. xmlstring.c
  144. xmlunicode.c
  145. xmlwriter.c
  146. xpath.c
  147. xpointer.c
  148. xzlib.c
  149. xzlib.h