tests: more automated quote adjustment

Relax initial regexp to match more instances, but add a
filter to avoid some invalid conversions.  Run this:

git grep -l "\`[^']*'" tests | xargs perl -pi -e '$q=q"'\''";' \
  -e '$q="$q\\$q$q"; /(= ?\`|\`expr|\`echo|\Q$q\E)/ and next;' \
  -e ' s/\`([^'\''"]*?'\'')/'\''$1/g'
The last disjunct in the above (...) filter is to exempt
any line that contains this string: '\''
With quoting like that, converting a ` to ' is likely to cause trouble,
so we'll handle those manually.  Here are three examples where
the exemption is required:

  *': `link-to-dir/'\'': hard link not allowed for directory'*) ;;
  printf 'creating file `%s'\''\n' $f
  'mv: inter-device move failed: `%s'\'' to `%s'\'';'\

1 files changed, 3 insertions, 3 deletions

diff --git a/tests/misc/tr b/tests/misc/tr
index ba6e943c8..89f777757 100755
--- a/tests/misc/tr
+++ b/tests/misc/tr
@@ -112,7 +112,7 @@ my @Tests =
   ['rep-3', qw('a[b*513]c' '1[x*]2'), {IN=>'abc'}, {OUT=>'1x2'}],
   # Another couple octal repeat count tests.
   ['o-rep-1', qw('[b*08]' '[x*]'), {IN=>''}, {OUT=>''}, {EXIT=>1},
-   {ERR=>"$prog: invalid repeat count `08' in [c*n] construct\n"}],
+   {ERR=>"$prog: invalid repeat count '08' in [c*n] construct\n"}],
   ['o-rep-2', qw('[b*010]cd' '[a*7]BC[x*]'), {IN=>'bcd'}, {OUT=>'BCx'}],
 
   ['esc', qw('a\-z' A-Z), {IN=>'abc-z'}, {OUT=>'AbcBC'}],
@@ -141,9 +141,9 @@ my @Tests =
   # Ensure that these fail.
   # Prior to 2.0.20, each would evoke a failed assertion.
   ['empty-eq', qw('[==]' x), {IN=>''}, {OUT=>''}, {EXIT=>1},
-   {ERR=>"$prog: missing equivalence class character `[==]'\n"}],
+   {ERR=>"$prog: missing equivalence class character '[==]'\n"}],
   ['empty-cc', qw('[::]' x), {IN=>''}, {OUT=>''}, {EXIT=>1},
-   {ERR=>"$prog: missing character class name `[::]'\n"}],
+   {ERR=>"$prog: missing character class name '[::]'\n"}],
 
   # Weird repeat counts.
   ['repeat-bs-9', qw(abc '[b*\9]'), {IN=>'abcd'}, {OUT=>'[b*d'}],