tectonic: tidy up some Synctex-related pieces

Including a function that returned `int` that was exiting without a specified
return value (always amazes me that C lets you do that). It *looks* like the
Synctex test is now passing in debug as well as release mode now.

Author: pkgw

tectonic/synctex.c

@@ -152,7 +152,6 @@ synctex_init_command(void)
     synctex_ctxt.flags.output_p = 0;
 
     INTPAR(synctex) = 0; /* \synctex=0 : don't record stuff */
-    synctex_ctxt.flags.off = 0; /* we're not forcibly disabled though: user code can override */
 }
 
 
@@ -698,7 +697,6 @@ synctex_current(void)
 static inline int
 synctex_record_settings(void)
 {
-    CACHE_THE_EQTB;
     int len;
 
     if (NULL == synctex_ctxt.file)
@@ -723,7 +721,7 @@ synctex_record_preamble(void)
     int len = ttstub_fprintf(synctex_ctxt.file, "SyncTeX Version:%i\n", SYNCTEX_VERSION);
 
     if (len > 0) {
-        synctex_ctxt.total_length = len;
+        synctex_ctxt.total_length = len; /* XXX: should this be `+=`? */
         return 0;
     }
 
@@ -751,7 +749,7 @@ synctex_record_anchor(void)
     int len = ttstub_fprintf(synctex_ctxt.file, "!%i\n", synctex_ctxt.total_length);
 
     if (len > 0) {
-        synctex_ctxt.total_length = len;
+        synctex_ctxt.total_length = len; /* XXX: should this be `+=`? */
         ++synctex_ctxt.count;
         return 0;
     }
@@ -765,10 +763,13 @@ synctex_record_content(void)
 {
     int len = ttstub_fprintf(synctex_ctxt.file, "Content:\n");
 
-    if (len > 0)
+    if (len > 0) {
         synctex_ctxt.total_length += len;
-    else
-        synctexabort();
+        return 0;
+    }
+
+    synctexabort();
+    return -1;
 }
 
 static inline int

tectonic/xetexd.h

@@ -687,7 +687,6 @@ scaled base_x_height;
 scaled base_width, base_height;
 scaled accent_width, accent_height;
 scaled delta;
-integer synctex_options;
 
 /*:1683*/
 

tectonic/xetexini.c

@@ -3687,7 +3687,7 @@ initialize_primitives(void)
     primitive(S(immediate), EXTENSION, IMMEDIATE_CODE);
     primitive(S(setlanguage), EXTENSION, SET_LANGUAGE_CODE);
 
-    primitive(S(synctex), ASSIGN_INT, INT_BASE + 83);
+    primitive(S(synctex), ASSIGN_INT, INT_BASE + INT_PAR__synctex);
 
     no_new_control_sequence = true;
 }
@@ -3730,8 +3730,6 @@ tt_run_engine(char *dump_name, char *input_file_name)
 
     /* Not sure why these get custom initializations. */
 
-    synctex_options = INT_MAX;
-
     if (file_line_error_style_p < 0)
         file_line_error_style_p = 0;