gitk: use -profile tcl8 on encoding conversions

gitk in the prior commit learned to apply -profile tcl8 to all input
data streams, avoiding errors on non-binary data streams whose encoding
is not utf-8. But, gitk also consumes binary data streams (generally blobs
from commits), and internally decodes this to support various displays.

With Tcl9, errors occur in this decoding for the same reasons described
in the previous commit: basically, the underlying data was not validated
to conform to the given encoding, and this source encoding may not be
utf-8. gitk performs this decoding using Tcl's '[encoding convert from'
operator.

For example, the 7th commit in gitk's history has the extended ascii
value 0xA9, so

	gitk 9a40c50

in gitk's repository raises an exception. The error log has:

unexpected byte sequence starting at index 11: '\xA9'
    while executing
"encoding convertfrom $diffencoding $line"
    (procedure "parseblobdiffline" line 135)
    invoked from within
"parseblobdiffline $ids $line"
    (procedure "getblobdiffline" line 16)
    invoked from within
"getblobdiffline file6 9a40c50"
    ("eval" body line 1)
    invoked from within
"eval $script"
    (procedure "dorunq" line 11)
    invoked from within
"dorunq"
    ("after" script)

This problem has a similar fix to the prior issue: we must use the tlc8
profile when converting this data. Do so, again only on Tcl9 as Tcl8.6
does not recognize -profile, and only Tcl 9.0 makes strict the default.

Signed-off-by: Mark Levedahl <[email protected]>

Author: mark987

gitk

@@ -28,6 +28,13 @@ if {[package vcompare $::tcl_version 9.0] >= 0} {
         chan configure $f -profile tcl8
         return $f
     }
+    proc convertfrom args {
+        return [encoding convertfrom -profile tcl8 {*}$args]
+    }
+} else {
+    proc convertfrom args {
+        return [encoding convertfrom {*}$args]
+    }
 }
 
 ######################################################################
@@ -7849,7 +7856,7 @@ proc gettreeline {gtf id} {
         if {[string index $fname 0] eq "\""} {
             set fname [lindex $fname 0]
         }
-        set fname [encoding convertfrom utf-8 $fname]
+        set fname [convertfrom utf-8 $fname]
         lappend treefilelist($id) $fname
     }
     if {![eof $gtf]} {
@@ -8111,7 +8118,7 @@ proc gettreediffline {gdtf ids} {
             if {[string index $file 0] eq "\""} {
                 set file [lindex $file 0]
             }
-            set file [encoding convertfrom utf-8 $file]
+            set file [convertfrom utf-8 $file]
             if {$file ne [lindex $treediff end]} {
                 lappend treediff $file
                 lappend sublist $file
@@ -8256,7 +8263,7 @@ proc makediffhdr {fname ids} {
     global ctext curdiffstart treediffs diffencoding
     global ctext_file_names jump_to_here targetline diffline
 
-    set fname [encoding convertfrom utf-8 $fname]
+    set fname [convertfrom utf-8 $fname]
     set diffencoding [get_path_encoding $fname]
     set i [lsearch -exact $treediffs($ids) $fname]
     if {$i >= 0} {
@@ -8318,7 +8325,7 @@ proc parseblobdiffline {ids line} {
 
     if {![string compare -length 5 "diff " $line]} {
         if {![regexp {^diff (--cc|--git) } $line m type]} {
-            set line [encoding convertfrom utf-8 $line]
+            set line [convertfrom utf-8 $line]
             $ctext insert end "$line\n" hunksep
             continue
         }
@@ -8367,7 +8374,7 @@ proc parseblobdiffline {ids line} {
         makediffhdr $fname $ids
 
     } elseif {![string compare -length 16 "* Unmerged path " $line]} {
-        set fname [encoding convertfrom utf-8 [string range $line 16 end]]
+        set fname [convertfrom utf-8 [string range $line 16 end]]
         $ctext insert end "\n"
         set curdiffstart [$ctext index "end - 1c"]
         lappend ctext_file_names $fname
@@ -8380,7 +8387,7 @@ proc parseblobdiffline {ids line} {
 
     } elseif {![string compare -length 2 "@@" $line]} {
         regexp {^@@+} $line ats
-        set line [encoding convertfrom $diffencoding $line]
+        set line [convertfrom $diffencoding $line]
         $ctext insert end "$line\n" hunksep
         if {[regexp { \+(\d+),\d+ @@} $line m nl]} {
             set diffline $nl
@@ -8409,18 +8416,18 @@ proc parseblobdiffline {ids line} {
             $ctext insert end "$line\n" filesep
         }
     } elseif {$currdiffsubmod != "" && ![string compare -length 3 "  >" $line]} {
-        set line [encoding convertfrom $diffencoding $line]
+        set line [convertfrom $diffencoding $line]
         $ctext insert end "$line\n" dresult
     } elseif {$currdiffsubmod != "" && ![string compare -length 3 "  <" $line]} {
-        set line [encoding convertfrom $diffencoding $line]
+        set line [convertfrom $diffencoding $line]
         $ctext insert end "$line\n" d0
     } elseif {$diffinhdr} {
         if {![string compare -length 12 "rename from " $line]} {
             set fname [string range $line [expr 6 + [string first " from " $line] ] end]
             if {[string index $fname 0] eq "\""} {
                 set fname [lindex $fname 0]
             }
-            set fname [encoding convertfrom utf-8 $fname]
+            set fname [convertfrom utf-8 $fname]
             set i [lsearch -exact $treediffs($ids) $fname]
             if {$i >= 0} {
                 setinlist difffilestart $i $curdiffstart
@@ -8439,12 +8446,12 @@ proc parseblobdiffline {ids line} {
             set diffinhdr 0
             return
         }
-        set line [encoding convertfrom utf-8 $line]
+        set line [convertfrom utf-8 $line]
         $ctext insert end "$line\n" filesep
 
     } else {
         set line [string map {\x1A ^Z} \
-                      [encoding convertfrom $diffencoding $line]]
+                      [convertfrom $diffencoding $line]]
         # parse the prefix - one ' ', '-' or '+' for each parent
         set prefix [string range $line 0 [expr {$diffnparents - 1}]]
         set tag [expr {$diffnparents > 1? "m": "d"}]
@@ -12433,7 +12440,7 @@ proc cache_gitattr {attr pathlist} {
             foreach row [split $rlist "\n"] {
                 if {[regexp "(.*): $attr: (.*)" $row m path value]} {
                     if {[string index $path 0] eq "\""} {
-                        set path [encoding convertfrom utf-8 [lindex $path 0]]
+                        set path [convertfrom utf-8 [lindex $path 0]]
                     }
                     set path_attr_cache($attr,$path) $value
                 }