Add a simple .editorconfig file (#747)

This ensures that (most) compatible editors will insert tabs into the makefiles and spaces elsewhere. We also don't want trailing whitespace to be stripped when we edit the test files. Finally, it helps to open testinput1 in Latin-1 and testinput2 in UTF-8 mode. All this can be automated.

The editorconfig file should work with any text editor - although note that VS Code needs an extension to make use of it.

Author: NWilson

.editorconfig

@@ -0,0 +1,23 @@
+# EditorConfig helps ensure that files are opened in editors with the correct
+# settings, regardless of the editor or platform. See http://editorconfig.org.
+
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+end_of_line = lf
+
+[Makefile.am]
+indent_style = tab
+
+[*.bat]
+end_of_line = crlf
+
+[testdata/*]
+insert_final_newline = false
+trim_trailing_whitespace = false
+
+[testdata/test{input,output}{1,2,3,3A,3B,3C,6,28,29}]
+charset = latin1

Makefile.am

@@ -338,13 +338,13 @@ src/config.h.generic: configure.ac
 	cs=$(srcdir)/config.status; test ! -f $$cs.aside || mv -f $$cs.aside $$cs
 	test -f _generic/src/config.h
 	perl -n \
-	  -e 'BEGIN{$$blank=0;}' \
-	  -e 'if(/(.+?)\s*__attribute__ \(\(visibility/){print"$$1\n";$$blank=0;next;}' \
-	  -e 'if(/LT_OBJDIR/){print"/* This is ignored unless you are using libtool. */\n";}' \
-	  -e 'if(/^#define\s((?:HAVE|SUPPORT|STDC)_\w+)/){print"/* #undef $$1 */\n";$$blank=0;next;}' \
-	  -e 'if(/^#define\s(?!PACKAGE|VERSION)(\w+)/){print"#ifndef $$1\n$$_#endif\n";$$blank=0;next;}' \
-	  -e 'if(/^\s*$$/){print unless $$blank; $$blank=1;} else{print;$$blank=0;}' \
-	  _generic/src/config.h >$@
+		-e 'BEGIN{$$blank=0;}' \
+		-e 'if(/(.+?)\s*__attribute__ \(\(visibility/){print"$$1\n";$$blank=0;next;}' \
+		-e 'if(/LT_OBJDIR/){print"/* This is ignored unless you are using libtool. */\n";}' \
+		-e 'if(/^#define\s((?:HAVE|SUPPORT|STDC)_\w+)/){print"/* #undef $$1 */\n";$$blank=0;next;}' \
+		-e 'if(/^#define\s(?!PACKAGE|VERSION)(\w+)/){print"#ifndef $$1\n$$_#endif\n";$$blank=0;next;}' \
+		-e 'if(/^\s*$$/){print unless $$blank; $$blank=1;} else{print;$$blank=0;}' \
+		_generic/src/config.h >$@
 	rm -rf _generic
 
 MAINTAINERCLEANFILES += src/pcre2.h.generic src/config.h.generic
@@ -847,20 +847,20 @@ EXTRA_DIST += \
 # they don't, add their working files to CLEANFILES.
 
 CLEANFILES += \
-        testSinput \
-        testSoutput \
-        test3input \
-        test3output \
-        test3outputA \
-        test3outputB \
-        testtry \
-        teststdout \
-        teststderr \
-        teststderrgrep \
-        testtemp1grep \
-        testtemp2grep \
-        testtrygrep \
-        testNinputgrep
+  testSinput \
+  testSoutput \
+  test3input \
+  test3output \
+  test3outputA \
+  test3outputB \
+  testtry \
+  teststdout \
+  teststderr \
+  teststderrgrep \
+  testtemp1grep \
+  testtemp2grep \
+  testtrygrep \
+  testNinputgrep
 
 testoutput-clean:
 	-rm -rf testoutput8 testoutput8-jit testoutput8-dfa