[PATCH v1 02/11] git-gui: refactor browser / blame argument parsing

[Mark Levedahl <mlevedahl@gmail.com>]

git-gui has subcommands blame and browser, both of which accept a
pathname, possibly preceded by a commit-ish item to specify a revision.
Also, blame can take a first argument that gives a line number to focus.

The command line parser for the above is more complex than needed, and
cannot work without a worktree as the pathname objects are checked
against the current worktree for existence. This also precludes naming a
directory or file that does not exist on the currently checked out
branch.

So, replace this with a simpler parser that looks at argument number and
number of arguments to know what value to expect. The blame and browser
backends already have error checking with diagnostic information, so
defer most error checking to those. Also, allow a line-number selection
to be given and silently ignored for the browser, further simplifying
this code.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
---
 git-gui.sh | 66 +++++++++++++-----------------------------------------
 1 file changed, 16 insertions(+), 50 deletions(-)

diff --git a/git-gui.sh b/git-gui.sh
index 6048f92..a951fcd 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -2986,51 +2986,34 @@ blame {
 	set head {}
 	set path {}
 	set jump_spec {}
-	set is_path 0
+	set nargs [llength $argv]
+	if {$nargs < 1} {
+		usage
+	}
+	set argn 0
 	foreach a $argv {
-		set p [file join $_prefix $a]
+		set argn [expr {$argn + 1}]
 
-		if {$is_path || [file exists $p]} {
-			if {$path ne {}} usage
-			set path [normalize_relpath $p]
-			break
-		} elseif {$a eq {--}} {
-			if {$path ne {}} {
-				if {$head ne {}} usage
-				set head $path
-				set path {}
+		if {$argn < $nargs} {
+			# revision or line number
+			if {[regexp {^--line=(\d+)$} $a a lnum]} {
+				set jump_spec [list $lnum]
+			} else {
+				set head $a
 			}
-			set is_path 1
-		} elseif {[regexp {^--line=(\d+)$} $a a lnum]} {
-			if {$jump_spec ne {} || $head ne {}} usage
-			set jump_spec [list $lnum]
-		} elseif {$head eq {}} {
-			if {$head ne {}} usage
-			set head $a
-			set is_path 1
-		} else {
-			usage
-		}
-	}
-	unset is_path
-
-	if {$head ne {} && $path eq {}} {
-		if {[string index $head 0] eq {/}} {
-			set path [normalize_relpath $head]
-			set head {}
 		} else {
-			set path [normalize_relpath $_prefix$head]
-			set head {}
+			set path [normalize_relpath $a]
 		}
 	}
 
 	if {$head eq {}} {
 		load_current_branch
+		set head $current_branch
 	} else {
 		if {[regexp [string map "@@ [expr $hashlength - 1]" {^[0-9a-f]{1,@@}$}] $head]} {
 			if {[catch {
-					set head [git rev-parse --verify $head]
-				} err]} {
+				set head [git rev-parse --verify $head]
+			} err]} {
 				if {[tk windowingsystem] eq "win32"} {
 					tk_messageBox -icon error -title [mc Error] -message $err
 				} else {
@@ -3046,26 +3029,9 @@ blame {
 	switch -- $subcommand {
 	browser {
 		if {$jump_spec ne {}} usage
-		if {$head eq {}} {
-			if {$path ne {} && [file isdirectory $path]} {
-				set head $current_branch
-			} else {
-				set head $path
-				set path {}
-			}
-		}
 		browser::new $head $path
 	}
 	blame   {
-		if {$head eq {} && ![file exists $path]} {
-			catch {wm withdraw .}
-			tk_messageBox \
-				-icon error \
-				-type ok \
-				-title [mc "git-gui: fatal error"] \
-				-message [mc "fatal: cannot stat path %s: No such file or directory" $path]
-			exit 1
-		}
 		blame::new $head $path $jump_spec
 	}
 	}
-- 
2.54.0.99.14