From 3b106a380356f1bb0c03d899c8a41d90d148ca9e Mon Sep 17 00:00:00 2001
From: Philip Sargent <philip.sargent@klebos.com>
Date: Sat, 15 Oct 2022 17:25:41 +0300
Subject: [PATCH] fix PCTEXT better in dis-laying tunnel files

---
 core/views/drawings.py | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/core/views/drawings.py b/core/views/drawings.py
index e922433..073f017 100644
--- a/core/views/drawings.py
+++ b/core/views/drawings.py
@@ -22,6 +22,22 @@ todo='''- Need to check if invalid query string is invalid, or produces multiple
 and render a user-friendly error page.
 '''
 
+def unescape(input):
+    '''These look like HTML entities, but they are not. They are tunnel-specific encodings
+    '''
+    codes = {
+        "&space;" : " ",
+        "&quot;" : "\"",
+        "&tab;" : "\t",
+        "&backslash;" : "\\",
+        "&newline;" : "\n\t",
+        "&apostrophe": "'",
+    }
+    for c in codes:
+        #print(c, codes[c])
+        input = input.replace(c, codes[c])
+    return input
+    
 
 def dwgallfiles(request):
     '''Report on all the drawing files in the system. These were loaded by parsing the entire directory tree
@@ -54,10 +70,9 @@ def dwgfilesingle(request, path):
                     print(f'- before reading any {encoding}')
                     lines = f.readlines()
                 #print(f'- finished reading {encoding}')
-                #print(f'- {len(lines)=}')
                 clean = []
                 for l in lines:
-                    clean.append(l.replace('&amp;','@').replace('&','&amp;').replace('@', '&amp;'))
+                    clean.append(unescape(l)) # deals with strangely embedded survex file
                 #print(f'- Cleaned and stripped.')
                 try:
                     return HttpResponse(content=clean, content_type="text/xml")