Fix parsing of AM reply messages

- use std::string instead of malloced array for ACCT_MGR_OP::global_prefs_xml
- use copy_element_contents() instead of dup_element_contents()
  to get global prefs.
  The latter uses fgets instead of fgetc,
  so it requires that close tag be on a line by itself.
  TODO: don't use fgets anywhere in XML parsing.
- fix a bug in copy_element_contents() where it consumes an extra character

client/acct_mgr.cpp

@@ -66,10 +66,7 @@ int ACCT_MGR_OP::do_rpc(
     error_num = ERR_IN_PROGRESS;
     error_str = "";
     via_gui = _via_gui;
-    if (global_prefs_xml) {
-        free(global_prefs_xml);
-        global_prefs_xml = 0;
-    }
+    global_prefs_xml = "";
 
     // if null URL, detach from current AMS
     //
@@ -406,10 +403,10 @@ int ACCT_MGR_OP::parse(FILE* f) {
             continue;
         }
         if (xp.match_tag("global_preferences")) {
-            retval = dup_element_contents(
+            retval = copy_element_contents(
                 f,
                 "</global_preferences>",
-                &global_prefs_xml
+                global_prefs_xml
             );
             if (retval) {
                 msg_printf(NULL, MSG_INTERNAL_ERROR,
@@ -434,6 +431,7 @@ int ACCT_MGR_OP::parse(FILE* f) {
         if (xp.match_tag("user_keywords")) {
             retval = ami.user_keywords.parse(xp);
             if (retval) return retval;
+            continue;
         }
         if (log_flags.unparsed_xml) {
             msg_printf(NULL, MSG_INFO,
@@ -705,9 +703,9 @@ void ACCT_MGR_OP::handle_reply(int http_op_retval) {
 
         // process prefs if any
         //
-        if (global_prefs_xml) {
+        if (!global_prefs_xml.empty()) {
             retval = gstate.save_global_prefs(
-                global_prefs_xml, ami.master_url, ami.master_url
+                global_prefs_xml.c_str(), ami.master_url, ami.master_url
             );
             if (retval) {
                 msg_printf(NULL, MSG_INTERNAL_ERROR, "Can't save global prefs");

client/acct_mgr.h

@@ -145,7 +145,7 @@ struct ACCT_MGR_OP: public GUI_HTTP_OP {
     std::string error_str;
     std::vector<AM_ACCOUNT> accounts;
     double repeat_sec;
-    char* global_prefs_xml;
+    std::string global_prefs_xml;
     char host_venue[256];
     bool got_rss_feeds;
     std::vector<RSS_FEED>rss_feeds;
@@ -162,7 +162,7 @@ struct ACCT_MGR_OP: public GUI_HTTP_OP {
         via_gui = false;
         error_num = BOINC_SUCCESS;
         repeat_sec = 60.0;
-        global_prefs_xml = 0;
+        global_prefs_xml = "";
         safe_strcpy(host_venue, "");
         got_rss_feeds = false;
     }

client/client_state.h

@@ -418,7 +418,7 @@ struct CLIENT_STATE {
         const char* fname = GLOBAL_PREFS_FILE_NAME,
         const char* override_fname = GLOBAL_PREFS_OVERRIDE_FILE
     );
-    int save_global_prefs(char* prefs, char* url, char* sched);
+    int save_global_prefs(const char* prefs, char* url, char* sched);
     double available_ram();
     double max_available_ram();
     int check_suspend_processing();

client/cs_prefs.cpp

@@ -722,7 +722,7 @@ void CLIENT_STATE::read_global_prefs(
 }
 
 int CLIENT_STATE::save_global_prefs(
-    char* global_prefs_xml, char* master_url, char* scheduler_url
+    const char* global_prefs_xml, char* master_url, char* scheduler_url
 ) {
     FILE* f = boinc_fopen(GLOBAL_PREFS_FILE_NAME, "w");
     if (!f) return ERR_FOPEN;

lib/parse.cpp

@@ -256,15 +256,16 @@ int copy_element_contents(FILE* in, const char* end_tag, string& str) {
     while (1) {
         c = fgetc(in);
         if (c == EOF) break;
-        if (n >= end_tag_len) {
-            const char* p = str.c_str() + n - end_tag_len;
-            if (!strcmp(p, end_tag)) {
-                str.erase(n-end_tag_len, end_tag_len);
-                return 0;
-            }
-        }
         str += c;
         n++;
+        if (n < end_tag_len) {
+            continue;
+        }
+        const char* p = str.c_str() + n - end_tag_len;
+        if (!strcmp(p, end_tag)) {
+            str.erase(n-end_tag_len, end_tag_len);
+            return 0;
+        }
     }
     return ERR_XML_PARSE;
 }