Compare version numbers properly

getssl uses cURL's version to determine what command
options are valid.

The previous shortcuts will fail when curl V8.10 is
released.  (8.9 is greater than 8.10).  V8 is planned
for release, in part to avoid a minor version of 100,
which also would fail.

check_version() will compare full or partial version
strings by component, and is true if $1 is at least $2.

getssl

@@ -269,6 +269,7 @@
 # 2021-07-30 Prefer API V2 when both offered (tlhackque) (#690) (2.40)
 # 2021-07-30 Run tests with -d to catch intermittent failures, Use fork's repo for upgrade tests. (tlhackque) (#692) (2.41)
 # 2021-08-26 Improve upgrade check & make upgrade do a full install when possible (tlhackque) (#694) (2.42)
+# 2021-09-02 Fix version compare - cURL v8 may have single digit minor numbers. (tlhackque) (2.43)
 # ----------------------------------------------------------------------------------------
 
 case :$SHELLOPTS: in
@@ -277,7 +278,7 @@ esac
 
 PROGNAME=${0##*/}
 PROGDIR="$(cd "$(dirname "$0")" || exit; pwd -P;)"
-VERSION="2.42"
+VERSION="2.43"
 
 # defaults
 ACCOUNT_KEY_LENGTH=4096
@@ -924,6 +925,27 @@ check_getssl_upgrade() { # check if a more recent release is available
   graceful_exit
 }
 
+check_version() { # true if version string $1 >= $2
+  local v1 v2 i n1 n2 n
+  # $1 and $2 can be different lengths, but all parts must be numeric
+  if [[ "$1" == "$2" ]] ; then return 0; fi
+  local IFS='.'
+  # shellcheck disable=SC2206
+  v1=($1)
+  # shellcheck disable=SC2206
+  v2=($2)
+  n1="${#v1[@]}"
+  n2="${#v2[@]}"
+  if [[ "$n1" -ge "$n2" ]] ; then n="$n1" ; else n="$n2" ; fi
+  for ((i=0; i<n; i++)) do
+    n1="${v1[$i]:-0}"
+    n2="${v2[$i]:-0}"
+    if [[ $((10#$n1)) -gt $((10#$n2)) ]] ; then return 0 ; fi
+    if [[ $((10#$n1)) -lt $((10#$n2)) ]] ; then return 1 ; fi
+  done
+  return 0
+}
+
 clean_up() { # Perform pre-exit housekeeping
   umask "$ORIG_UMASK"
   if [[ $VALIDATE_VIA_DNS == "true" ]]; then
@@ -2346,8 +2368,7 @@ send_signed_request() { # Sends a request to the ACME server, signed with your p
   dp="$TEMP_DIR/curl.dump"
 
   CURL="curl ${_NOMETER} "
-  # shellcheck disable=SC2072
-  if [[ ! "${_CURL_VERSION}" < "7.33" ]]; then
+  if check_version "${_CURL_VERSION}" "7.33" ; then
     CURL="$CURL --http1.1 "
   fi
 
@@ -2846,8 +2867,7 @@ requires mktemp
 #       This would help with debugging transfer errors.
 
 _CURL_VERSION="$(curl -V | head -1 | cut -d' ' -f2 )"
-# shellcheck disable=SC2072
-if [[ ! "${_CURL_VERSION}" < "7.67" ]]; then
+if check_version "${_CURL_VERSION}" "7.67" ; then
     _NOMETER="--no-progress-meter"
 fi