From b6b65a05c03b34b4b7064b2153b6ddf851100044 Mon Sep 17 00:00:00 2001
From: Darshit Shah <address@hidden>
Date: Fri, 12 Sep 2014 13:33:20 +0530
Subject: [PATCH] Handle multibyte characters in progressbar

This commit fixes a bug in the progressbar implementation wherein
filenames with multibyte characters were not handled correctly.
---
 ChangeLog      |  4 ++++
 bootstrap.conf |  1 +
 src/progress.c | 44 +++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8b693be..c4e7809 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2014-09-12  Darshit Shah  <address@hidden>
+
+	* bootstrap.conf: Add GNULib module mbiter
+
 2014-07-25  Darshit Shah  <address@hidden>
 
 	* .gitignore: Add a gitignore file for the project.
diff --git a/bootstrap.conf b/bootstrap.conf
index 516bbb6..bbfb38f 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -49,6 +49,7 @@ iconv
 iconv-h
 listen
 maintainer-makefile
+mbiter
 mbtowc
 mkdir
 mkstemp
diff --git a/src/progress.c b/src/progress.c
index e9182cc..86cdbce 100644
--- a/src/progress.c
+++ b/src/progress.c
@@ -37,6 +37,7 @@ as that of the covered work.  */
 #include <unistd.h>
 #include <signal.h>
 #include <wchar.h>
+#include <mbiter.h>
 
 #include "progress.h"
 #include "utils.h"
@@ -812,8 +813,37 @@ count_cols (const char *mbs)
     }
   return cols;
 }
+
+static int
+cols_to_bytes (const char *mbs, const int cols, int *ncols)
+{
+  int p_cols = 0, bytes = 0;
+  mbchar_t mbc;
+  mbi_iterator_t iter;
+  mbi_init (iter, mbs, strlen(mbs));
+  while (p_cols < cols && mbi_avail (iter))
+    {
+      mbc = mbi_cur (iter);
+      p_cols += mb_width (mbc);
+      /* The multibyte character has exceeded the total number of columns we
+       * have available. The remaining bytes will be padded with a space. */
+      if (p_cols > cols)
+        {
+          p_cols -= mb_width (mbc);
+          break;
+        }
+      bytes += mb_len (mbc);
+      mbi_advance (iter);
+    }
+  *ncols = p_cols;
+  return bytes;
+}
 #else
 # define count_cols(mbs) ((int)(strlen(mbs)))
+# define cols_to_bytes(mbs, cols, *ncols) do {  \
+    *ncols = cols;                              \
+    bytes = cols;                               \
+}while (0)
 #endif
 
 static const char *
@@ -885,6 +915,7 @@ create_image (struct bar_progress *bp, double dl_total_time, bool done)
 
   struct bar_progress_hist *hist = &bp->hist;
   int orig_filename_len = strlen (bp->f_download);
+  int orig_filename_cols = count_cols (bp->f_download);
 
   /* The progress bar should look like this:
      file xx% [=======>             ] nnn.nnK 12.34KB/s  eta 36m 51s
@@ -935,13 +966,20 @@ create_image (struct bar_progress *bp, double dl_total_time, bool done)
   else
     {
       int offset;
+      int offset_bytes, offset_start, col;
+      int *cols_ret = &col;
 
       if (((orig_filename_len > MAX_FILENAME_LEN) && !opt.noscroll) && !done)
-        offset = ((int) bp->tick) % (orig_filename_len - MAX_FILENAME_LEN);
+        offset = ((int) bp->tick) % (orig_filename_cols - MAX_FILENAME_LEN);
       else
         offset = 0;
-      memcpy (p, bp->f_download + offset, MAX_FILENAME_LEN);
-      p += MAX_FILENAME_LEN;
+      offset_start = cols_to_bytes (bp->f_download, offset, cols_ret);
+      offset_bytes = cols_to_bytes (bp->f_download + offset_start, MAX_FILENAME_LEN, cols_ret);
+      memcpy (p, bp->f_download + offset_start, offset_bytes);
+      p += offset_bytes;
+      int padding = MAX_FILENAME_LEN - *cols_ret;
+      for (;padding;padding--)
+          *p++ = ' ';
       *p++ = ' ';
     }
 
-- 
2.1.0