kopt: honor TESSDATA_PREFIX environment variable

Don't override it by default, but honor it if present.

frontend/document/koptinterface.lua

@@ -20,7 +20,10 @@ local util = require("util")
 
 local KoptInterface = {
     ocrengine = "ocrengine",
-    tessocr_data = DataStorage:getDataDir() .. "/data",
+    -- If `$TESSDATA_PREFIX` is set, don't override it: let libk2pdfopt honor it
+    -- (which includes checking for data in both `$TESSDATA_PREFIX/tessdata` and
+    -- in `$TESSDATA_PREFIX/` on more recent versions).
+    tessocr_data = not os.getenv('TESSDATA_PREFIX') and DataStorage:getDataDir().."/data" or nil,
     ocr_lang = "eng",
     ocr_type = 3, -- default 0, for more accuracy use 3
     last_context_size = nil,

platform/android/llapp_main.lua

@@ -16,9 +16,6 @@ end
 -- path to primary external storage partition
 local path = android.getExternalStoragePath()
 
--- set TESSDATA_PREFIX env var
-C.setenv("TESSDATA_PREFIX", path.."/koreader/data", 1)
-
 -- create fake command-line arguments
 -- luacheck: ignore 121
 if android.isDebuggable() then

platform/cervantes/koreader.sh

@@ -53,9 +53,6 @@ if [ -n "${fail}" ] && [ "${fail}" -eq 0 ]; then
     exec ./koreader.sh "$@"
 fi
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export dict directory
 export STARDICT_DATA_DIR="data/dict"
 

platform/kindle/koreader.sh

@@ -177,9 +177,6 @@ if [ -n "${fail}" ] && [ "${fail}" -eq 0 ]; then
     exec ./koreader.sh ${REEXEC_FLAGS} "${@}"
 fi
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export dict directory
 export STARDICT_DATA_DIR="data/dict"
 

platform/kobo/koreader.sh

@@ -146,9 +146,6 @@ if [ -n "${fail}" ] && [ "${fail}" -eq 0 ]; then
     exec ./koreader.sh "${@}"
 fi
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export dict directory
 export STARDICT_DATA_DIR="data/dict"
 

platform/kobo/nickel.sh

@@ -13,7 +13,7 @@ export QT_GSTREAMER_PLAYBIN_AUDIOSINK_DEVICE_PARAMETER=bluealsa:DEV=00:00:00:00:
 # shellcheck disable=SC2164
 cd /
 unset OLDPWD
-unset LC_ALL TESSDATA_PREFIX STARDICT_DATA_DIR EXT_FONT_DIR
+unset LC_ALL STARDICT_DATA_DIR EXT_FONT_DIR
 unset KO_DONT_GRAB_INPUT
 unset FBINK_FORCE_ROTA
 

platform/pocketbook/koreader.app

@@ -78,9 +78,6 @@ ko_update_check() {
 # we're always starting from our working directory
 cd ${KOREADER_DIR} || exit
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export dict directory
 export STARDICT_DATA_DIR="data/dict"
 

platform/remarkable/koreader.sh

@@ -72,9 +72,6 @@ if [ -n "${fail}" ] && [ "${fail}" -eq 0 ]; then
     exec ./koreader.sh "${@}"
 fi
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export dict directory
 export STARDICT_DATA_DIR="data/dict"
 

platform/ubuntu-touch/koreader.sh

@@ -7,9 +7,6 @@ KOREADER_DIR="${0%/*}"
 # we're always starting from our working directory
 cd "${KOREADER_DIR}" || exit
 
-# export trained OCR data directory
-export TESSDATA_PREFIX="data"
-
 # export external font directory
 export EXT_FONT_DIR="${HOME}/fonts"