[issue2950] hg diff seems to not preserve whitespace changes

[Nathan Michaels]

New submission from Nathan Michaels <nmichaels at gmail.com>:

I've got this happening in 1.8.3, but I couldn't find any references to it. 

The problem is that hg diff seems to be ignoring whitespace (as though it had been passed "-
b" or "-w", but it hadn't. To make this happen, I put a snippet of mockup assembler code in a 
file in a new repository. After adding and committing it, I changed one line and the spacing 
on other lines, as you'll see below.

Here's my shell history showing it in action:


$ hg log
changeset:   1:3a3315c3161c
tag:         tip
user:        me
date:        Wed Aug 10 12:00:23 2011 -0400
summary:     Changed a number.

changeset:   0:a5e29a057ab5
user:        me
date:        Wed Aug 10 11:59:03 2011 -0400
summary:     A file with formatted code.

$ hg update 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ ls
file.S
$ hg cat -r 0 file.S
LabelName:
    { move r3,  lr      ; fnop                 }
    { move r12, r7      ; shri r6, CONSTANT, 7 }
    { bbs  r1,  someBit ; addi r4, r4,       9 }
$ hg cat -r 1 file.S
LabelName:
    { move r3,  lr      ; fnop                  }
    { move r12, r7      ; shri r6, CONSTANT, 12 }
    { bbs  r1,  someBit ; addi r4, r4,       9  }
$ hg diff -c 1 file.S
diff -r a5e29a057ab5 -r 3a3315c3161c file.S
--- a/file.S    Wed Aug 10 11:59:03 2011 -0400
+++ b/file.S    Wed Aug 10 12:00:23 2011 -0400
@@ -1,4 +1,4 @@
 LabelName:
     { move r3,  lr      ; fnop                 }
-    { move r12, r7      ; shri r6, CONSTANT, 7 }
+    { move r12, r7      ; shri r6, CONSTANT, 12 }
     { bbs  r1,  someBit ; addi r4, r4,       9 }
$ hg diff -c 1 file.S > DIFF
$ hg import --no-commit DIFF
applying DIFF
$ cat file.S
LabelName:
    { move r3,  lr      ; fnop                 }
    { move r12, r7      ; shri r6, CONSTANT, 12 }
    { bbs  r1,  someBit ; addi r4, r4,       9 }

As you can see, the }s don't line up in the diff version but they do in the cat version.

----------
messages: 17104
nosy: nmichaels
priority: bug
status: unread
title: hg diff seems to not preserve whitespace changes

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<http://mercurial.selenic.com/bts/issue2950>
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