Fix pango escaping and refactor escape_markup_text

Fixes #2674.

The cause of the issue was in get_pango_layout. When we call
pango_parse_markup, `text` is the escaped string, and the unescaped
string is then computed and written to `buf`. We were then passing the
unescaped string to pango_layout_set_markup, but this function needs the
escaped string. `buf` is not needed and has been removed.

The other part of this PR refactors escape_markup_text to remove the
dest_length argument and removes the -1 return value on error. It now
assumes that you've allocated dest to the correct length.

1 files changed, 17 insertions, 40 deletions

diff --git a/common/pango.c b/common/pango.c
index ea71ac4a..dd27991b 100644
--- a/common/pango.c
+++ b/common/pango.c
@@ -7,66 +7,45 @@
 #include <stdlib.h>
 #include <string.h>
 #include "log.h"
+#include "stringop.h"
 
-int escape_markup_text(const char *src, char *dest, int dest_length) {
-        int length = 0;
+size_t escape_markup_text(const char *src, char *dest) {
+        size_t length = 0;
+        if (dest) {
+                dest[0] = '\0';
+        }
 
         while (src[0]) {
                 switch (src[0]) {
                 case '&':
                         length += 5;
-                        if (dest && dest_length - length >= 0) {
-                                dest += sprintf(dest, "%s", "&amp;");
-                        } else {
-                                dest_length = -1;
-                        }
+                        lenient_strcat(dest, "&amp;");
                         break;
                 case '<':
                         length += 4;
-                        if (dest && dest_length - length >= 0) {
-                                dest += sprintf(dest, "%s", "&lt;");
-                        } else {
-                                dest_length = -1;
-                        }
+                        lenient_strcat(dest, "&lt;");
                         break;
                 case '>':
                         length += 4;
-                        if (dest && dest_length - length >= 0) {
-                                dest += sprintf(dest, "%s", "&gt;");
-                        } else {
-                                dest_length = -1;
-                        }
+                        lenient_strcat(dest, "&gt;");
                         break;
                 case '\'':
                         length += 6;
-                        if (dest && dest_length - length >= 0) {
-                                dest += sprintf(dest, "%s", "&apos;");
-                        } else {
-                                dest_length = -1;
-                        }
+                        lenient_strcat(dest, "&apos;");
                         break;
                 case '"':
                         length += 6;
-                        if (dest && dest_length - length >= 0) {
-                                dest += sprintf(dest, "%s", "&quot;");
-                        } else {
-                                dest_length = -1;
-                        }
+                        lenient_strcat(dest, "&quot;");
                         break;
                 default:
-                        length += 1;
-                        if (dest && dest_length - length >= 0) {
-                                *(dest++) = *src;
-                        } else {
-                                dest_length = -1;
+                        if (dest) {
+                                dest[length] = *src;
+                                dest[length + 1] = '\0';
                         }
+                        length += 1;
                 }
                 src++;
         }
-        // if we could not fit the escaped string in dest, return -1
-        if (dest && dest_length == -1) {
-                return -1;
-        }
         return length;
 }
 
@@ -75,11 +54,9 @@ PangoLayout *get_pango_layout(cairo_t *cairo, const char *font,
         PangoLayout *layout = pango_cairo_create_layout(cairo);
         PangoAttrList *attrs;
         if (markup) {
-                char *buf;
                 GError *error = NULL;
-                if (pango_parse_markup(text, -1, 0, &attrs, &buf, NULL, &error)) {
-                        pango_layout_set_markup(layout, buf, -1);
-                        free(buf);
+                if (pango_parse_markup(text, -1, 0, &attrs, NULL, NULL, &error)) {
+                        pango_layout_set_markup(layout, text, -1);
                 } else {
                         wlr_log(WLR_ERROR, "pango_parse_markup '%s' -> error %s", text,
                                         error->message);