[ jedit-Patches-3543916 ] Fixed Issue replacing start of line match with empty string

Patches item #3543916, was opened at 2012-07-13 23:48
Message generated for change (Comment added) made by jarekczek
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Category: texteditor
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Swetha (swetha1910)
>Assigned to: Jarek Czekalski (jarekczek)
Summary: Fixed Issue replacing start of line match with empty string

Initial Comment:
Problem:  With regular expressions enabled, and if the search pattern having '^' then the 'replace all' 
option  performs repeated replacing for every character in the line and not 'start of the line' matches. 

Details:
Example I:
Input:
Twinkle Twinkle
Little Star
How I wonder what you
are

Search for: ^.
meaning I want a search for the first character of every line

Replace with:
replace every matched character with nothing (literally deleting the first character from every line)

Expected Output when I click REPLACE ALL:
winkle Twinkle
ittle Star
ow I wonder what you
re

What actually happens here is that the buffer is emptied because every character is replaced with an empty string.

Output when I click REPLACE:
winkle Twinkle
Little Star
How I wonder what you
are

Output when I click REPLACE AND FIND:
winkle Twinkle
Little Star
How I wonder what you
are

NOTE: In the last case, the find function will now match 'w' in the second line input text.

Example II:
Input:
Twinkle Twinkle
Little Star
How I wonder what you
are

Search for:  ^.
meaning I want a search for the first character of every line

Replace with: p
replace every matched character with the letter 'p'

Expected Output when I click REPLACE ALL:
pwinkle Twinkle
pittle Star
pow I wonder what you
pre

Output when I click REPLACE:
pwinkle Twinkle
Little Star
How I wonder what you
are

Output when I click REPLACE AND FIND:
pinkle Twinkle
Little Star
How I wonder what you
are

NOTE: In the last case, the find function will now match 'L' in the input text because in regular expressions
'^' symbol should check only for the beginning of the line.
But the result in the current version empties the buffer whenever replace all is given for Example 1 which is
wrong. It violates the meaning of the regular expression '^' itself.

Example III:
Input text:
AABBBA
Search: ^A
Expected Output: ABBBA
But Actual Result of the current version: BBBA

How the bug was fixed:
1. Check if the regex option is selected
2. If yes, then check if the search pattern has '^'
3. If yes, then set the offset value accordingly. 

Patch Details:
Version of jEdit : 4.5.2
Platform: Windows
Edited file: SearchAndReplace.java
Package: org/gjt/sp/jedit/Search

----------------------------------------------------------------------

>Comment By: Jarek Czekalski (jarekczek)
Date: 2012-08-01 10:47

Message:
1. It's not the output of svn diff
2. Still can't compile "string"

----------------------------------------------------------------------

Comment By: Swetha (swetha1910)
Date: 2012-07-31 00:08

Message:
It's fine with me. Leave it in original state.

----------------------------------------------------------------------

Comment By: Jarek Czekalski (jarekczek)
Date: 2012-07-30 13:01

Message:
For you the condition is more logical. For the original author it was more
logical to make infinite loop. If it is not necessary to change this line,
I suggest to leave it in the original state. Would you agree?

----------------------------------------------------------------------

Comment By: Swetha (swetha1910)
Date: 2012-07-30 11:09

Message:
There is no particular meaning for an infinite loop in the _replace
function (SearchAndReplace.java file). The replace should not take place
beyond the end value and so is more logical when the condition "offset <
end" is added. 

----------------------------------------------------------------------

Comment By: Jarek Czekalski (jarekczek)
Date: 2012-07-27 10:49

Message:
This patch does not compile, because of this line:

string current_line = buffer.getLineOfOffset(offset);

Cannot find symbol string.

If you resubmit the patch please pay attention to following:
1. prepare it using "svn diff" command run from the root directory
(directory containing org directory), preferrably having checked out the
most recent version (from trunk)
2. check type of whitespace you insert (match the ones used in the file)
3. explain, to help me understand the patch: why is the condition "offset <
end" in "for" loop needed now, while previously it wasn't there

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=300588&aid=3543916&group_id=588

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