Fix strdup_and_subst_obj() so that calls not involving simple labels collapse \\...

Without this, users cannot get a lone backslash in an HTML-label or tooltip if it
preceded G, E, N, etc.
We don't do this for simple label text, as it is later processed to handle \n, \r, etc.
and collapses \\ to \ at that time.

diff --git a/lib/common/labels.c b/lib/common/labels.c
index 54f09befc03e8698d2b8704bf50a9093de989480..c657fe425a7e34a51c2cc0f51988cfd234488723 100644 (file)
--- a/lib/common/labels.c
+++ b/lib/common/labels.c
@@ -16,6 +16,8 @@
 #include "htmltable.h"
 #include <limits.h>
 
+static char *strdup_and_subst_obj0 (char *str, void *obj, int escBackslash);
+
 static void storeline(graph_t *g, textlabel_t *lp, char *line, char terminator)
 {
     pointf size;
@@ -165,7 +167,10 @@ textlabel_t *make_label(void *obj, char *str, int kind, double fontsize, char *f
     }
     else {
         assert(kind == LT_NONE);
-       rv->text = strdup_and_subst_obj(str, obj);
+       /* This call just processes the graph object based escape sequences. The formatting escape
+         * sequences (\n, \l, \r) are processed in make_simple_label. That call also replaces \\ with \.
+         */
+       rv->text = strdup_and_subst_obj0(str, obj, 0);
         switch (rv->charset) {
        case CHAR_LATIN1:
            s = latin1ToUTF8(rv->text);
@@ -276,7 +281,13 @@ void emit_label(GVJ_t * job, emit_state_t emit_state, textlabel_t * lp)
     obj->emit_state = old_emit_state;
 }
 
-char *strdup_and_subst_obj(char *str, void *obj)
+/* strdup_and_subst_obj0:
+ * Replace various escape sequences with the name of the associated
+ * graph object. A double backslash \\ can be used to avoid a replacement.
+ * If escBackslash is true, convert \\ to \; else leave alone. All other dyads 
+ * of the form \. are passed through unchanged.
+ */
+static char *strdup_and_subst_obj0 (char *str, void *obj, int escBackslash)
 {
     char c, *s, *p, *t, *newstr;
     char *tp_str = "", *hp_str = "";
@@ -370,11 +381,12 @@ char *strdup_and_subst_obj(char *str, void *obj)
            case 'L':
                newlen += l_len;
                break; 
-#ifdef ESCAPE_BACKSLASH
            case '\\':
-               newlen += 1;
-               break; 
-#endif
+               if (escBackslash) {
+                   newlen += 1;
+                   break; 
+               }
+               /* Fall through */
            default:  /* leave other escape sequences unmodified, e.g. \n \l \r */
                newlen += 2;
            }
@@ -419,11 +431,12 @@ char *strdup_and_subst_obj(char *str, void *obj)
            case 'L':
                for (t = l_str; (*p = *t++); p++);
                break;
-#ifdef ESCAPE_BACKSLASH
            case '\\':
-               *p++ = '\\';
-               break;
-#endif
+               if (escBackslash) {
+                   *p++ = '\\';
+                   break; 
+               }
+               /* Fall through */
            default:  /* leave other escape sequences unmodified, e.g. \n \l \r */
                *p++ = '\\';
                *p++ = c;
@@ -437,6 +450,14 @@ char *strdup_and_subst_obj(char *str, void *obj)
     return newstr;
 }
 
+/* strdup_and_subst_obj:
+ * Processes graph object escape sequences; also collapses \\ to \.
+ */
+char *strdup_and_subst_obj(char *str, void *obj)
+{
+    return strdup_and_subst_obj0 (str, obj, 1);
+}
+
 /* return true if *s points to &[A-Za-z]*;      (e.g. &Ccedil; )
  *                          or &#[0-9]*;        (e.g. &#38; )
  *                          or &#x[0-9a-fA-F]*; (e.g. &#x6C34; )