Re: GNU sed fails to insert tab at beginning of line in a certain way

[Paolo Bonzini]

On 11/03/2010 06:21 PM, Warren Turkal wrote:
> I don't really understand why the \t doesn't work when it comes first in
> the append command. Is that expected behavior?

It looks like you have to double the backslash to have the desired 
effect--but only at the beginning of the line.  So, this is certainly a 
bug and this patch fixes it.

diff --git a/sed/compile.c b/sed/compile.c
index b2fb825..33bf74c 100644
--- a/sed/compile.c
+++ b/sed/compile.c
@@ -897,10 +897,7 @@ read_text(buf, leadin_ch)
   if (leadin_ch == EOF)
     return;

-  if (leadin_ch != '\n')
-    add1_buffer(pending_text, leadin_ch);
-
-  ch = inchar();
+  ch = (leadin_ch == '\n') ? inchar() : leadin_ch;
   while (ch != EOF && ch != '\n')
     {
       if (ch == '\\')
@@ -1181,7 +1178,16 @@ compile_program(vector)
            bad_prog(_(EXPECTED_SLASH));
        
          if (ch == '\\')
-           ch = inchar();
+            {
+              ch = inchar();
+              if (ch != '\n')
+                {
+                  if (posixicity == POSIXLY_BASIC && ch != '\n')
+                    bad_prog(_(EXPECTED_SLASH));
+                  savchar(ch);
+                  ch = '\\';
+                }
+            }
          else
            {
              if (posixicity == POSIXLY_BASIC)


Paolo