From 3198051254614679f0bc78ca5f1bb406616f64ad Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Sun, 24 Apr 2016 14:00:50 +0200
Subject: [PATCH] Allow group specification in ArgInstall options

The option that add a line to the existing multi-line options
(e.g. -installTheme which adds to -themeNames) now can specify the
line should be added within a group, by prefixing the line with
"# GROUPNAME\n" (where \ and n separate characters). If a group of
that name already exists, the line to add  is insert immediately after
the group header line. If not, the group is created, by adding both the
group header line and the line to add, as well as an "# end" line to
terminate the group.
---
 args.h |   29 ++++++++++++++++++++++++-----
 1 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/args.h b/args.h
index 85e8765..8b8fe8e 100644
--- a/args.h
+++ b/args.h
@@ -961,7 +961,7 @@ ParseArgs(GetFunc get, void *cl)
   char argValue[MAX_ARG_LEN];
   ArgDescriptor *ad;
   char start;
-  char *q;
+  char *q, *r, *s;
   int i, octval;
   char ch;
   int posarg = 4; // default is game file
@@ -1241,10 +1241,29 @@ ParseArgs(GetFunc get, void *cl)
 
     case ArgInstall:
       q = *(char **) ad->argLoc;
-      if((saveDate == 0 || saveDate - dateStamp < 0) && !strstr(q, argValue) ) {
-        int l = strlen(q) + strlen(argValue);
-        *(char **) ad->argLoc = malloc(l+2);
-        snprintf(*(char **) ad->argLoc, l+2, "%s%s\n", q, argValue);
+      r = NULL; s = argValue;
+      if(argValue[0] == '#') { // group specification
+        r = strstr(argValue, "\\n");
+        if(r) *r++ = '\n', *r++ = NULLCHAR, s = r, r = argValue; // split s into line-to-add (s) and group (r)
+      }
+      if((saveDate == 0 || saveDate - dateStamp < 0) && !strstr(q, s) ) { // not seen before, and line does not occur yet
+        int l = strlen(q) + strlen(s);
+        if(r) { // must be put in group r
+          char *p = strstr(q, r);
+          if(p) { // group already exists
+            p += strlen(r); // determine insertion point (immediately after group header line)
+            *(char **) ad->argLoc = malloc(l+2);
+            *p++ = NULLCHAR; // spit old value (q) at insertion point into q and p
+            snprintf(*(char **) ad->argLoc, l+2, "%s%s\n%s", q, s, p); // insert (with newline)
+          } else { // group did not exist, create at end
+            l += strlen(r) + 8;
+            *(char **) ad->argLoc = malloc(l);
+            snprintf(*(char **) ad->argLoc, l, "%s%s%s\n# end\n", q, r, s);
+          }
+        } else { // no group, just add line at end
+          *(char **) ad->argLoc = malloc(l+2);
+          snprintf(*(char **) ad->argLoc, l+2, "%s%s\n", q, s);
+        }
         free(q);
       }
       break;
-- 
1.7.0.4