libremessages:flag: Fix several things (also librexgettext)

 - Fix a bug where it panicked if given an odd number of sub-headings.
 - Document the the ability to include sub-headings.
 - Fix librexgettext's handling of it.  It only worked correctly for times
   when it was only called once in a program, or when it was only ever
   called with exactly one flag/description pair (and no headings).

1 files changed, 78 insertions, 23 deletions

diff --git a/src/lib/librexgettext b/src/lib/librexgettext
index 22a6df2..c82b9ae 100755
--- a/src/lib/librexgettext
+++ b/src/lib/librexgettext
@@ -65,49 +65,104 @@ xgettext-sh() {
 
 xgettext-flag() {
 	{
-		declare -i x=0
+		# Stage 1: Generate
+		#
+		# Get all of the arguments to `flag`.  Because `flag`
+		# takes an arbitrary number of arguments, just iterate
+		# through arg1, arg2, ... argN; until we've come up
+		# empty 3 times.  Why 3?  Because each flag takes 2
+		# arguments, and because we don't keep track of which
+		# one of those we're on, waiting for 3 empties ensures
+		# us that we've had a complete "round" with nothing.
+		#
+		# Why can't I just do i+=2, and not have to keep track
+		# of empties?  Because, we also allow for arguments
+		# ending in a colon to be headings, which changes the
+		# offsets.
+		declare -i empties=0
 		declare -i i
-		for (( i=1; x < 3; i++ )); do
+		for (( i=1; empties < 3; i++ )); do
 			local out
 			out="$(xgettext-sh --keyword="flag:$i,\"$i\"" "$@")"
 			if [[ -n $out ]]; then
 				printf -- '%s\n' "$out"
 			else
-				x+=1
+				empties+=1
 			fi
 		done
 	} | whitespace-collapse | sed '/^\#, sh-format/d' | {
-		declare -i i
-
-		IFS=''
-		local segments=()
+		# Stage 2: Parse
+		#
+		# Read in the lines, and group them into an array of
+		# (multi-line) msgs.  This just makes working with
+		# them easier.
+		local msgs=()
+		declare -i i=-1
 		local re='^#\. ([0-9]+)$'
+		IFS=''
 		local line
 		while read -r line; do
 			if [[ $line =~ $re ]]; then
-				i=${BASH_REMATCH[1]}
-			else
-				segments[$i]+="$line"$'\n'
+				i+=1
 			fi
+			msgs[$i]+="$line"$'\n'
 		done
-
-		declare -i last=$(printf '%s\n' "${!segments[@]}"|sed -n '$p')
-
+		# Stage 3: Sort
+		#
+		# Now, we have the `msgs` array, and it is
+		# sorted such that it is all of the arg1's to `flag`,
+		# then all of the arg2's, then all of the arg3's, and
+		# so on.  We want to re-order them such that it's all
+		# of the args for the first invocation then all of the
+		# args for the second; and so on.
+		#
+		# We do this by simply sorting them by the location
+		# that they appear in the file.  Then, when we see the
+		# argument number go back down to 1, we know that a
+		# new invocation has started!
 		IFS=$'\n'
-		local flag=true
-		for (( i=1; i <= last; i++ )); do
-			if $flag; then
-				local lines=(${segments[$i]})
+		local locations=($(
+			local i
+			for i in "${!msgs[@]}"; do
+				declare -i arg row
+				local lines=(${msgs[$i]})
+				arg=${lines[0]#'#. '}
+				row=${lines[1]##*:}
+				printf '%d.%d %d\n' "$row" "$arg" "$i"
+			done | sort -n
+		))
+		# Stage 4: Output
+		#
+		# Now, we prune out the arguments that aren't
+		# localizable.  Also, remove the "#." comment lines.
+		# As explained above (in stage 3), when we see $arg go
+		# to 1, that's the beginning of a new invocation.
+		local expectflag=true
+		local location
+		for location in "${locations[@]}"; do
+			IFS=' .'
+			local row arg i
+			read -r row arg i <<<"$location"
+			local msg="${msgs[$i]#*$'\n'}"
+			# Now we operate based on $row, $arg, and $msg
+			if [[ $arg == 1 ]]; then
+				expectflag=true
+			fi
+			if $expectflag; then
+				IFS=$'\n'
+				local lines=(${msg})
 				if [[ ${lines[1]} == *':"' ]]; then
-					printf -- '%s\n' "${segments[$i]}"
+					# We expected a flag, but got
+					# a heading
+					printf -- '%s\n' "$msg"
 				else
-					flag=false
+					# We expected a flag, and got
+					# one!
+					expectflag=false
 				fi
 			else
-				if [[ -n ${segments[$i]} ]]; then
-					printf -- '%s\n' "${segments[$i]}"
-				fi
-				flag=true
+				printf -- '%s\n' "$msg"
+				expectflag=true
 			fi
 		done
 	}