Merge branch 'kb/maint-diff-ws-check'

* kb/maint-diff-ws-check:
diff: handle lines containing only whitespace and tabs better
test-lib: extend test_decode_color to handle more color codes

diff --combined t/test-lib.sh
index 744f4364c2b41724e9c395c386fd8048338a2435,49527a675b15c05344e101de98b1d3335b9c983f..38e5a59ff7877b3d2624574ecb9584803fe46152
--- 1/t/test-lib.sh
--- 2/t/test-lib.sh
+++ b/t/test-lib.sh
@@@ -238,20 -238,49 +238,53 @@@ test_set_editor () 
  }
  
  test_decode_color () {
-       sed     -e 's/.\[1m/<WHITE>/g' \
-               -e 's/.\[31m/<RED>/g' \
-               -e 's/.\[32m/<GREEN>/g' \
-               -e 's/.\[33m/<YELLOW>/g' \
-               -e 's/.\[34m/<BLUE>/g' \
-               -e 's/.\[35m/<MAGENTA>/g' \
-               -e 's/.\[36m/<CYAN>/g' \
-               -e 's/.\[m/<RESET>/g'
+       awk '
+               function name(n) {
+                       if (n == 0) return "RESET";
+                       if (n == 1) return "BOLD";
+                       if (n == 30) return "BLACK";
+                       if (n == 31) return "RED";
+                       if (n == 32) return "GREEN";
+                       if (n == 33) return "YELLOW";
+                       if (n == 34) return "BLUE";
+                       if (n == 35) return "MAGENTA";
+                       if (n == 36) return "CYAN";
+                       if (n == 37) return "WHITE";
+                       if (n == 40) return "BLACK";
+                       if (n == 41) return "BRED";
+                       if (n == 42) return "BGREEN";
+                       if (n == 43) return "BYELLOW";
+                       if (n == 44) return "BBLUE";
+                       if (n == 45) return "BMAGENTA";
+                       if (n == 46) return "BCYAN";
+                       if (n == 47) return "BWHITE";
+               }
+               {
+                       while (match($0, /\x1b\[[0-9;]*m/) != 0) {
+                               printf "%s<", substr($0, 1, RSTART-1);
+                               codes = substr($0, RSTART+2, RLENGTH-3);
+                               if (length(codes) == 0)
+                                       printf "%s", name(0)
+                               else {
+                                       n = split(codes, ary, ";");
+                                       sep = "";
+                                       for (i = 1; i <= n; i++) {
+                                               printf "%s%s", sep, name(ary[i]);
+                                               sep = ";"
+                                       }
+                               }
+                               printf ">";
+                               $0 = substr($0, RSTART + RLENGTH, length($0) - RSTART - RLENGTH + 1);
+                       }
+                       print
+               }
+       '
  }
  
 +nul_to_q () {
 +      perl -pe 'y/\000/Q/'
 +}
 +
  q_to_nul () {
        perl -pe 'y/Q/\000/'
  }
@@@ -366,15 -395,6 +399,15 @@@ test_have_prereq () 
        test $total_prereq = $ok_prereq
  }
  
 +test_declared_prereq () {
 +      case ",$test_prereq," in
 +      *,$1,*)
 +              return 0
 +              ;;
 +      esac
 +      return 1
 +}
 +
  # You are not expected to call test_ok_ and test_failure_ directly, use
  # the text_expect_* functions instead.
  
@@@ -427,17 -447,17 +460,17 @@@ test_skip () 
                        break
                esac
        done
 -      if test -z "$to_skip" && test -n "$prereq" &&
 -         ! test_have_prereq "$prereq"
 +      if test -z "$to_skip" && test -n "$test_prereq" &&
 +         ! test_have_prereq "$test_prereq"
        then
                to_skip=t
        fi
        case "$to_skip" in
        t)
                of_prereq=
 -              if test "$missing_prereq" != "$prereq"
 +              if test "$missing_prereq" != "$test_prereq"
                then
 -                      of_prereq=" of $prereq"
 +                      of_prereq=" of $test_prereq"
                fi
  
                say_color skip >&3 "skipping test: $@"
@@@ -451,10 -471,9 +484,10 @@@
  }
  
  test_expect_failure () {
 -      test "$#" = 3 && { prereq=$1; shift; } || prereq=
 +      test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
        test "$#" = 2 ||
        error "bug in the test script: not 2 or 3 parameters to test-expect-failure"
 +      export test_prereq
        if ! test_skip "$@"
        then
                say >&3 "checking known breakage: $2"
@@@ -470,10 -489,9 +503,10 @@@
  }
  
  test_expect_success () {
 -      test "$#" = 3 && { prereq=$1; shift; } || prereq=
 +      test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
        test "$#" = 2 ||
        error "bug in the test script: not 2 or 3 parameters to test-expect-success"
 +      export test_prereq
        if ! test_skip "$@"
        then
                say >&3 "expecting success: $2"
@@@ -515,12 -533,11 +548,12 @@@ test_expect_code () 
  # Usage: test_external description command arguments...
  # Example: test_external 'Perl API' perl ../path/to/test.pl
  test_external () {
 -      test "$#" = 4 && { prereq=$1; shift; } || prereq=
 +      test "$#" = 4 && { test_prereq=$1; shift; } || test_prereq=
        test "$#" = 3 ||
        error >&5 "bug in the test script: not 3 or 4 parameters to test_external"
        descr="$1"
        shift
 +      export test_prereq
        if ! test_skip "$descr" "$@"
        then
                # Announce the script to reduce confusion about the
@@@ -986,13 -1003,11 +1019,13 @@@ case $(uname -s) i
        # no POSIX permissions
        # backslashes in pathspec are converted to '/'
        # exec does not inherit the PID
 +      test_set_prereq MINGW
        ;;
  *)
        test_set_prereq POSIXPERM
        test_set_prereq BSLASHPSPEC
        test_set_prereq EXECKEEPSPID
 +      test_set_prereq NOT_MINGW
        ;;
  esac